LIBRARY 

OF  THE 

UNIVERSITY  .OF  CALIFORNIA. 


Class 


THE 
SCHOOL   HOUSE 

Its 

^ 

Heating  and  Ventilation 


BY 
JOSEPH   A.  MOORE 

INSPECTOR     OF     PUBLIC     BUILDINGS 
STATE    OF    MASSACHUSETTS 
r 


V* 

V 


RAl 


Copyrighted,  1905 
By  JOSEPH  A.  MOORE 


Published  by  the  Author 

BOSTON,  MASS. 


GRIFFITH  -STILLINGS    PRESS 
368  CONGRESS  ST.,  BOSTON 


INTRODUCTION 


THE  writer  having  been  for  the  last  eighteen  years  engaged  in 
the  inspection  of  public  buildings  in  Massachusetts,  and  in  super- 
vising the  construction  of  and  testing  the  various  methods  of  heat- 
ing and  ventilation,  especially  in  schoolhouses,  presents  to  those 
interested  in  our  public  schools  some  suggestions  as  to  the  construc- 
tion and  the  heating  and  ventilation  of  such  buildings.  The  class 
of  buildings  selected  are  those  of  small  or  moderate  size,  of  which 
many  are  erected  each  year. 

It  is  not  the  writer's  intention  to  give  theoretical  or  scientific 
descriptions  or  arguments,  but  simply  such  methods  and  plans  as 
have  been  proved  by  actual  experience  to  give  satisfactory  results. 

Many  of  the  plans  were  designed  by  the  writer  for  the  annual 
official  reports  of  the  late  Rufus  R.  Wade,  Chief  of  the  Massachu- 
setts District  Police 

The  method  of  setting  up  indirect  radiators,  as  shown  in  the 
plans  and  now  generally  adopted  in  Massachusetts,  was  designed  by 
the  writer,  and  first  published  in  drawings  which  formed  part  of 
the  official  exhibit  of  the  Inspection  Department  of  the  Massachu- 
setts District  Police  at  the  Columbian  Exposition  at  Chicago  in  1893, 
and  for  which  an  award  was  given. 

Other  plans  formed  part  of  the  exhibit  at  the  Paris  Exposition  in 
1900,  for  which  an  award  was  also  given,  and  at  the  Louisiana 
Purchase  Exposition  at  St.  Louis  in  1904,  for  which  a  gold  medal 
was  also  awarded  the  department. 

BOSTON,  MASS. 
1905. 


162631 


CONTENTS. 


PART   I. 

CHAPTER  I — The  schoolhouse,  location,  size  and  cost,  building 
committee,  plans,  Massachusetts  laws,  appropriation,  choice 
of  site,  height,  construction,  prevention  of  spread  of  fire, 
means  to  extinguish  fire,  basement,  corridors,  vestibules,  exits, 
stairways,  fire  escapes,  doors,  windows,  class  rooms,  seating, 
blackboards,  clocks,  thermometers,  pictures  and  plaster  casts, 
telephones  and  fire-alarm  boxes. 

CHAPTER  II — Air,  composition,  impurities,  respiration,  products 
of  respiration,  amount  of  air  required,  humidity,  lights,  test- 
ing purity  of  air,  Wolpert's  test,  preparation  of  lime  water, 
measurement  of  air,  wind  velocity  and  pressure. 

CHAPTER  III — Amount  of  air  required  by  Massachusetts  regula- 
tions, some  erroneous  ideas  of  ventilation,  circulation  of  air, 
u  systems,"  location  of  inlets  and  outlets,  exhaust  and  plenum 
methods,  leakage,  velocity,  beams  and  projections  below  ceil- 
ing, ceiling  ventilation  in  halls,  location  of  heating  apparatus, 
deflectors,  mixing  dampers,  dampers  in  vent  flues,  flap  valves, 
force  and  direction  of  prevailing  winds,  adjustable  switch 
dampers,  location  of  discharge  from  vent  flues,  back  draft, 
caps  on  vent  flues,  testing  movement  of  air  currents. 

CHAPTER  IV — Tests  of  amount  of  air  supply  and  heat  in  school- 
rooms, difference  in  cost  of  heating  schoolhouses,  size  and 
construction  of  warm  air  ducts  and  flues,  wire  grills,  cast-iron 
registers,  mixing  dampers,  adjusting  dampers,  aspirating 
chimneys  and  vent  flues,  heat  in  vent  flues,  location  of  vent 
flue  heaters,  exhaust  fans,  amount  of  steam  heat  in  vent  flues, 
size  and  location  of  vent  openings,  chimneys,  location,  height 
and  area. 

CHAPTER  V — Boilers,  horse-power,  grate  surface,  heating  surface, 
determining  size  of  boiler,  shell,  heads,  tubes,  braces,  fittings 
and  appliances,  standard  sizes,  setting  smoke  flues,  U.S. 
Government  rule  for  safe  pressure,  Massachusetts  inspectors' 
rule,  water-tube  boilers,  upright,  tubular,  sectional  cast-iron, 
Massachusetts  inspectors'  requirements  for  fittings,  Massachu- 


vi  CONTENTS. 

/ 
setts  law  for  licensing  of  engineers  and  firemen  and  for  the 

inspection  of  steam  boilers. 

CHAPTER  VI — Steam-pipes,  size,  covering,  valves,  locating  pipes, 
radiators,  quantity,  location,  casing  radiators,  rule  for  calcu- 
lating amount  of  indirect  radiation,  automatic  heat  control. 

CHAPTER  VII — Furnaces,  use  in  small  buildings,  location,  con- 
struction, size,  wrought  and  cast-iron,  test  for  gas  leakage, 
brick  setting,  portable  type,  smoke-pipes,  pit,  air  supply  and 
mixing  valves,  location  as  to  air  supply,  cold  air  rooms,  com- 
bination of  furnace  and  steam  heating,  twin  connected  furnaces, 
combination  of  furnace  and  hot  water  heating,  fans  for  supply- 
ing air  to  furnaces,  electric  motors,  gas  engines,  water-motors. 

CHAPTER  VIII — Janitors,  duties  and  instructions  for  care  and 
management  of  heating  and  ventilating  appliances  in  school- 
houses. 

CHAPTER  IX — Sanitary  appliances  in  schoolhouses,  outside  sani- 
tary buildings. 

PART   II. 

PLATE  I  —  Plan  and  description  of  one-room  schoolhouse,  showing 
,  method  of  heating  and  ventilating. 

PLATES  II  and  III — Plan,  sections  and  description  of  oneiroom 
portable  schoolhouse,  showing  heating,  ventilating  apparatus 
and  circulation  of  air. 

PLATES  IV,  V  and  VI — Plans  and  description  of  two-room,  one- 
story  schoolhouse,  with  sections  of  heating  and  ventilating 
apparatus  and  circulation  of  air. 

PLATES  VII,  VIII,  and  IX — Plans  and  description  of  two-room, 
two-story  schoolhouse,  and  section  through  ventilating  shaft. 

PLATES  X,  XI,  XII,  XIII  and  XIV — Plans  and  description  of  four- 
room,  two-story  schoolhouse,  showing  fan  and  furnace  and 
sections  through  warm  air  and  vent  flues. 

PLATES  XV,  XVI  and  XVII  —  Plans  and  description  of  five-room 
two- story  schoolhouse,  steam  heated. 

PLATES  XVIII,  XIX  and  XX — Plans  and  description  of  six-room, 

two-story    schoolhouse,    with    combination    of     furnace    and 

steam  heating. 
PLATES  XXI,  XXII,  XXIII  and  XXIV— Plans  and  description  of 

seven-room,  two-story  grammar  schoolhouse,  with  sections  of 

steam  heating  and  ventilating  apparatus. 


CONTENTS.  vii 

PLATES  XXV,  XXVI,  XXVII  and  XXVIII— Plans  and  descrip- 
tion of  eight-room,  two-story  schoolhouse,  showing  steam 
heating  by  combination  of  a  fan  and  a  gravity  air  supply. 

PLATES  XXIX,  XXX,  XXXI  and  XXXII— Plans  and  description 
of  an  eight-room,  two-story  school,  steam  heated. 

PLATES  XXXIII,  XXXIV  and  XXXV— Plans  and  description  of 
small  two-story  high  school,  steam  heated. 

PLATES  XXXVI  and  XXXVII — Plans  for  sanitary  buildings. 

PLATE  XXXVIII — Plan,  section  and  description  of  a  direct-indirect 
(steam)  radiator. 

PLATE  XXXIX — Plan,  section  and  description  of  portable  furnace 
setting  for  small  hall  or  church. 

PLATE  XL — Section  and  description  of  foot- warmer  for  school- 
house  corridor. 

PLATE  XLI  —  Setting  for  one  horizontal  tubular  boiler. 

PLATES  XLII  and  XLIII  —  Sections  of  setting  for  one  horizontal 
tubular  boiler. 

PLATE  XLIV — Section  of  setting  for  two  horizontal  tubular  boilers. 

FIGURES. 

Numbers    1  to  9  —  Schoolhouse  furniture. 

10 — Prof.  Wolpert's  air  tester. 

11  —  Lime  water  apparatus. 

12 — Template  for  correcting  anemometer  blades. 

13 — Form  of  air  inlet  in  schoolroom. 

14 — Form  of  air  inlet  in  schoolroom. 

15,  16,  17  and  18  —  Position  of  anemometer  in  measuring 
air. 

19,  20  and  21 — Location  of  inlets  and  outlets  and  cir- 
culation of  air  in  schoolrooms. 

TABLES. 

1  — For  Wolpert's  air  test. 

2  —  Of  wind  velocity  and  pressure. 

3  —  Of  tests  of  amount  of  heat  and  air  in  schoolhouses. 

4  —  Of  tests  of  amount  of  heat  and  air  in  schoolhouses. 

5  —  Of  tests  of  amount  of  heat  and  air  in  schoolhouses. 

6  —  Of  tests  of  amount  of  heat  and  air  in  schoolhouses. 


viii  CONTENTS. 

7  — Relative  cost  of  fuel  in  schoolhouses. 

8  —  Of  boiler,  grate  and  heating  surfaces. 

9  — Of  area  of  grate  surface  and  tube  opening. 

10  —  Of  standard  boiler  tubes. 

11  —  Of  standard  sizes  of  boilers. 

12  —  Of  dimensions  of  brick  settings  for  boilers. 

13  —  Of  dimensions  of  brick  settings  for  boilers. 
14 —  Of  sizes  of  supply  and  return  steam-pipes. 

15  —  Of  areas  of  rectangular  openings. 

16  —  Of  areas  and  circumference  of  circles. 
17 — For  equalizing  diameter  of  pipes. 

18  —  Of  number  of  gallons  in  round  tanks. 

19  —  Of  capacity  of  pipes  and  registers. 

20  —  Of  weight  of  steel  bars  per  foot. 

21  — Of  standard  gauges. 

22  —  Of  weights  of  galvanized  sheets. 

23  —  Of  circumferences  of  circles  used  by  boiler  makers, 

24  —  Of  number  of  tubes  used  in  return  tubular  boilers. 

25  —  Of  dimensions  of  standard  wrought-iron  pipe. 

26  —  Of  expansion  of  metals. 

27  —  For  estimating  size  of  coal  bins. 


s/ry 


CHAPTER  I 


THE    SCHOOL  HOUSE. 

WHEN  it  becomes  desirable  for  a  city  or  town  to  erect  a 
new  schoolhouse,  some  of  the  first  questions  to  be 
decided  are  :  Where  shall  it  be  located,  and  what  is  to 
be  the  size  and  cost  ? 

The  first  question,  as  to  location,  is  usually  decided  by  deter- 
mining where  is  the  most  convenient  place  that  will  best  accom- 
modate the  greater  part  of  the  pupils  in  the  school  district. 

The  size,  by  the  number  of  pupils  to  be  provided  for,  and  the 
cost,  by  the  ability  or  disposition  of  the  city  or  town  to  appropriate 
the  requisite  amount  of  money  for  that  purpose. 

The  choice  of  location  is  often  a  matter  of  considerable  con- 
troversy, and  it  sometimes,  unfortunately,  depends  upon  the  power 
or  local  strength  of  the  contending  parties. 

It  should,  however,  be  determined  which  location  will  best 
serve  the  interests  of  the  greater  number  of  pupils,  and  should  be 
where  it  will  be  free  from  the  objections  of  noise  or  unfavorable 
surroundings. 

A  site  near  large  manufacturing  establishments,  or  where 
objectionable  noises,  gases  or  odors  are  produced,  should  be  avoided, 
also  one  where  unhealthy  conditions  may  exist. 

A  dry  and  healthy  location  should  be  selected  in  preference  to 
one  that  is  low  and  wet,  or  on  filled  ground. 

The  size  of  the  building  should  be  determined  by  the  number 
of  pupils  to  be  provided  for  in  the  district  in  wliich  the  building  is 
to  be  located.  Not  only  the  present  needs  of  the  district  should  be 
considered,  but  also  the  probable  increase  in  the  near  future. 

The  cost  and  character  of  the  building  will  depend  consider- 
ably upon  the  financial  ability  of  the  city  or  town.  It  is  not  true 
economy  to  attempt  to  build  too  large  a  building  for  too  little 
money,  or  to  reduce  the  cost  to  such  a  degree  as  will  necessitate 
the  omission  of  certain  essential  requisites  for  a  good  building. 

Where  this  is  done,  dissatisfaction  will  be  the  result  when  the 
building  is  completed. 

Erecting  a  large  and  poorly-constructed  building  for  the  sake  of 
obtaining  a  large  building  at  a  low  cost  will  in  the  future  prove 


2  THE    SCHOOL   HOUSE. 

more  expensive  and  unsatisfactory  than  if  a  smaller  but  well-con- 
structed one  is  built,  and  the  committee  having  charge  of  the  work 
will  eventually  receive  more  blame  than  thanks  for  their  work. 

When  a  city  or  town  decides  to  erect  a  new  schoolhouse,  it  is 
advisable  that  a  committee  be  appointed  and  authorized  to  procure 
plans,  specifications  and  bona  fide  estimates  of  the  cost. 

Where  possible,  the  committee  should  consist  of  one  or  more 
practical  business  men  and  builders,  and  also  one  or  more  repre- 
sentatives of  the  school  board. 

It  is  not  advisable  to  appoint  too  large  a  committee,  as  is  some- 
times the  case. 

With  a  large  committee  the  actual  work  is  usually  done  by  a  few 
members,  and  discussions  often  arise  which  delay  the  construction. 

A  committee  of  three  or  five  members  will  often  make  better 
progress  and  give  better  satisfaction  than  one  that  is  too  large. 

After  the  committee  has  been  appointed  it  is  advisable  for  them 
to  invite  a  limited  number  of  architects  who  have  had  experience 
in  schoolhouse  construction,  to  submit  competitive  plans.  The 
invitation  should  contain  a  brief  description  of  what  is  desired ;  the 
number  and  kind  of  rooms,  height  and  material  of  which  the  build- 
ing is  to  be  constructed,  whether  of  brick,  stone  or  wood,  the 
location,  and  also  such  special  features  as  may  be  desired. 

The  plans  submitted  should  show  the  system  and  method  of 
heating  and  ventilation.  Where  this  is  not  done  it  is  sometimes 
found  that  a  suitable  system  cannot  be  installed  without  making 
changes  in  the  building  plans. 

The  Massachusetts  law  requires  the  plans  and  specifications  for 
schoolhouses  to  be  filed  with  the  State  "  Inspector  of  Factories 
and  Public  Buildings"  of  the  district  in  which  the  building  is 
located  before  the  building  is  constructed,  and  is  as  follows  : 


Chapter  104,  Revised  Laws,  Massachusetts  (7902). 

OF  THE    INSPECTION   OF   BUILDINGS. 

*  *•»**•**•** 

SPECIFIC  REQUIREMENTS. 

SECTION  22.  No  building  which  is  designed  to  be  used,  in  whole  or  in 
part,  as  a  public  building,  public  or  private  institution,  schoolhouse,  church, 
theatre,  public  hall,  place  of  assemblage  or  place  of  public  resort,  and  no 
building  more  than  two  stories  in  height,  which  is  designed  to  be  used 
above  the  second  story,  in  whole  or  in  part,  as  a  factory,  workshop  or 
mercantile  or  other  establishment  and  has  accommodations  for  ten  or  more 
employees  above  said  story,  and  no  building  more  than  two  stories  in  height 


THE    SCHOOL    HOUSE.  3 

designed  to  be  used  above  the  second  story,  in  whole  or  in  part,  as  a  hotel, 
family  hotel,  apartment  house,  boarding  house,  lodging  house  or  tenement 
house,  and  has  ten  or  more  rooms  above  said  story,  shall  be  erected  until  a 
copy  of  the  plans  thereof  has  been  deposited  with  the  inspector  of  factories 
and  public  buildings  for  the  district  in  which  it  is  to  be  erected  by  the  person 
causing  its  erection,  or  by  the  architect  thereof.  Such  plans  shall  include 
the  method  of  ventilation  provided  therefor  and  a  copy  of  such  portion  of  the 
specifications  therefor  as  the  inspector  may  require.  Such  building  shall  not 
be  so  erected  without  sufficient  egresses  and  other  means  of  escape  from  fire, 
properly"  located  and  constructed.  The  certificate  of  the  inspector,  indorsed 
with  the  approval  of  the  chief  of  the  district  police,  shall  be  conclusive 
evidence  of  a  compliance  with  the  provisions  of  this  chapter  unless,  after  it 
*Ss  granted,  a  change  is  made  in  the  plans  or  specifications  of  such  egresses 
and  means  of  escape  without  a  new  certificate  therefor.  Such  inspector  may 
require  that  proper  fire  stops  shall  be  provided  in  the  floors,  walls  and 
partitions  of  such  building,  and  may  make  such  further  requirements  as  may 
be  necessary  or  proper  to  prevent  the  spread  of  fire  therein  or  its 
communication  from  any  steam  boiler  or  heating  apparatus. 

SECTION  23.  No  wooden  flue  or  air  duct  for  heating  or  ventilating 
purposes  shall  be  placed  in  any  building  which  is  subject  to  the  provisions 
of  sections  twenty-four  and  twenty-five  and  no  pipe  for  conveying  hot  air  or 
steam  in  such  building  shall  be  placed  or  remain  within  one  inch  of  any 
woodwork,  unless  protected  to  the  satisfaction  of  said  inspector  by  suitable 
guards  or  casings  of  incombustible  material. 

SECTION  24.  Whoever  erects  or  constructs  a  building,  or  an  architect  or 
other  person  who  draws  plans  or  specifications  or  superintends  the  erection 
or  construction  of  a  building,  in  violation  of  the  provisions  of  this  chapter, 
shall  be  punished  by  a  fine  of  not  less  than  fifty  nor  more  than  one  thousand 
dollars. 

SECTION  25.  A  building  which  is  used,  in  whole  or  in  part,  as  a  public 
building,  public  or  private  institution,  school  house,  church,  theatre,  public 
hall,  place  of  assemblage  or  place  of  public  resort,  and  a  building  in  which 
ten  or  more  persons  are  employed  above  the  second  story  in  a  factory,  work- 
shop, mercantile  and  other  establishment,  and  a  hotel,  family  hotel,  apart- 
ment house,  boarding  house,  lodging  house  or  tenement  house  in  which  ten 
or  more  persons  lodge  or  reside  above  the  second  story,  and  a  factory, 
workshop,  mercantile  or  other  establishment  the  owner,  lessee  or  occupant 
of  which  is  notified  in  writing  by  an  inspector  of  factories  and  public  build- 
ings that  the  provisions  of  this  chapter  are  deemed  by  him  applicable  thereto 
shall  be  provided  with  proper  egresses  or  other  means  of  escape  from  fire, 
sufficient  for  the  use  of  all  persons  accommodated,  assembled,  employed, 
lodged  or  resident  therein  ;  but  no  owner,  lessee  or  occupant  of  such  building 
shall  be  deemed  to  have  violated  this  provision  unless  he  has  been  notified 
in  writing  by  such  inspector  what  additional  egresses  or  means  of  escape 
from  fire  are  necessary  and  has  neglected  or  refused  to  supply  the  same. 
The  egresses  and  means  of  escape  shall  be  kept  unobstructed,  in  good  repair 
and  ready  for  use.  Stairways  on  the  outside  of  the  building  shall  have 
suitable  railed  landings-at  each  story  above  the  first,  accessible  at  each  story 
from  doors  or  windows,  and  such  landings,  doors  and  windows  shall  be 
kept  clear  of  ice,  snow  and  other  obstructions.  Portable  seats  shall  not  be 


4  THE    SCHOOL   HOUSE. 

allowed  in  the  aisles  or  passageways  of  such  buildings  during  any  service  or 
entertainment  held  therein.  If  the  inspector  so  directs  in  writing,  women 
or  children  shall  not  be  employed  in  a  factory,  workshop,  mercantile  or  other 
establishment,  in  a  room  above  the  second  story  from  which  there  is  only 
one  egress,  and  all  doors  and  windows  in  any  building  which  is  subject  to 
the  provisions  of  this  section  shall  open  outwardly,  and  every  room  above 
the  second  story  in  any  such  building,  in  which  ten  or  more  persons  are 
employed,  shall  be  provided  with  more  than  one  egress  by  stairways  or  by 
such  other  way  or  device,  approved  in  writing  by  the  inspector,  as  the  owner 
may  elect,  on  the  inside  or  outside  of  the  building,  placed  as  near  as  practi- 
cable at  each  end  of  the  room.  The  certificate  of  the  inspector  shall  be 
conclusive  evidence  of  a  compliance  with  such  requirements. 

SECTION  26.  Each  story  above  the  second  story  of  a  building  which  is* 
subject  to  the  provisions  of  the  preceding  section  shall  be  supplied  with 
means  of  extinguishing  fire,  consisting  of  pails  of  water  or  other  portable 
apparatus  or  of  a  hose  attached  to  a  suitable  water  supply  and  capable  of 
reaching  any  part  of  such  story ;  and  such  appliances  shall  be  kept  at  all 
times  ready  for  use  and  in  good  condition. 

********* 
SECTION  36.  The  audience  hall  in  a  building  which  is  erected  or  designed 
to  be  used  in  whole  or  in  part  as  a  theatre  or  in  which  any  change  or  altera- 
tion shall  be  made  for  the  purpose  of  using  it  as  a  theatre  shall  not  be  placed 
above  the  second  floor  of  said  building.  The  audience  hall  and  each  gallery 
of  every  such  building  shall,  respectively,  have  at  least  two  independent 
exits,  as  far  apart  as  may  be,  and  if  the  audience  hall  is  on  the  second  floor, 
the  stairways  from  said  floor  to  the  ground  floor  shall  be  enclosed  with  fire- 
proof walls  from  the  basement  floor  up,  and  shall  have  no  connection  with 
the  basement  or  first  floor  of  the  building.  Every  such  exit  shall  have  a 
width  of  at  least  twenty  inches  for  every  one  hundred  persons  which  such 
hall,  or  gallery  from  which  it  leads,  is  capable  of  holding;  but  two  or  more 
exits  of  the  same  aggregate  width  may  be  substituted  for  either  of  the  two 
required  exits.  None  of  the  required  exits  shall  be  less  than  five  feet  wide. 
SECTION  37.  The  proscenium  or  curtain  opening  of  all  theatres  shall 
have  a  fire  resisting  curtain  of  an  incombustible  material,  property  constructed 
and  operated  by  proper  mechanism.  The  certificate  of  the  inspector  of 
factories  and  public  buildings  shall  be  conclusive  evidence  of  a  compliance 
with  such  requirements. 

********* 
SECTION  44  If,  in  the  erection  of  an  iron  or  steel  framed  building  the 
spaces  between  the  girders  or  floor  beams  of  any  floor  are  not  filled  or 
covered  by  the  permanent  construction  of  said  floors  before  another  story  is 
added  to  the  building,  a  close  plank  flooring  shall  be  placed  and  maintained 
over  such  spaces,  from  the  time  when  the  beams  or  girders  are  placed  in 
position  until  said  permanent  construction  is  applied;  but  openings,  pro- 
tected by  a  strong  hand  railing  not  less  than  four  feet  high,  may  be  left 
through  said  floors  for  the  passage  of  workmen  or  material. 

SECTION  45.  In  the  construction  of  any  iron  or  steel  framed  building 
having  a  clear  story  of  twenty-five  feet  elevation  or  more,  a  staging  with  a 
close  plank  flooring  shall  be  placed  under  the  whole  extent  of  the  beams, 
girders  or  trusses  of  such  story  upon  which  iron  or  steel  workers  are 


THE   SCHOOL   HOUSE.  5 

working,  and  not  more  than  ten  feet  below  the  under  side  of  such  beams 
girders  and  trusses. 

SECTION  46.  Inspectors  of  factories  and  public  buildings  shall  enforce 
the  provisions  of  the  two  preceding  sections,  and  whoever  violates  any 
provision  thereof  shall  be  punished  by  a  fine  of  not  less  than  fifty  nor  more 
than  five  hundred  dollars  for  each  offence. 

********* 

SECTION  51.  The  supreme  judicial  court  or  the  superior  court  shall  have 
jurisdiction  in  equity,  upon  the  petition  of  an  inspector,  temporarily  or 
permanently  to  restrain  the  erection,  construction,  use  or  occupation  of  a 
building  in  violation  of  the  provisions  of  this  chapter. 

SECTION  52.  The  supreme  judicial  court  or  the  superior  court  shall  have 
jurisdiction  in  equity  to  restrain  the  illegal  placing,  maintenance  or  use  of 
any  building,  structure  or  other  thing.  It  may,  upon  the  petition  of  a  city 
or  town,  by  its  attorney,  for  such  relief,  require  the  removal  of  any  such 
building,  structure  or  other  thing  by  the  owner,  and  may  authorize  the  city 
or  town,  in  default  of  such  removal  by  the  owner,  to  remove  it  at  his 
expense.  The  provisions  of  this  section  shall  apply  to  such  buildings, 
structures  or  other  things  so  placed  which  were  maintained  or  used  prior  to, 
as  well  as  after,  the  second  day  of  May  in  the  year  eighteen  hundred  and 
ninety-nine.  Upon  such  petition,  the  defendant  shall  be  presumed  to  have 
acted  without  a  license  or  authority  until  he  proves  to  the  contrary. 

SECTION  53.  Sections  fifteen  to  eighteen,  inclusive,  twenty-two  to  twenty- 
six,  inclusive,  thirty,  thirty-one,  thirty-six,  thirty-seven,  forty-eight  to  fifty- 
one,  inclusive,  and  fifty-four  shall  not  apply  to  the  city  of  Boston. 

SECTION  54.  Cities  may  by  ordinance  provide  that  the  provisions  of 
sections  fifteen  to  eighteen,  inclusive,  twenty -two  to  twenty-six,  inclusive, 
thirty-six,  thirty-seven,  forty  eight  and  forty-nine  shall  apply  to  any  building 
of  three  or  more  stories  in  height  within  their  respective  limits. 

SECTION  55.  Whoever,  being  the  owner,  lessee  or  occupant  of  any 
building  or  room  described  in  section  twenty-two  violates  the  provisions  of 
sections  fifteen  to  eighteen,  inclusive,  twenty-two  to  twenty-six,  inclusive, 
thirty-six,  thirty-seven,  forty-eight  and  forty-nine,  shall  be  punished  by  a 
fine  of  not  less  than  fifty  nor  more  than  one  thousand  dollars. 

SECTION  56.  Whoever  violates  any  provision  of  this  chapter  for  which 
no  other  penalty  is  specifically  prescribed  shall  be  punished  by  a  fine  of  not 
more  than  one  hundred  dollars. 

Chapter  106,  Revised  Laws,  Massachusetts. 
SANITARY   PROVISIONS. 


* 


SECTION  54.  Every  public  building  and  every  school  house  shall  be  kept 
clean  and  free  from  effluvia  arising  from  any  drain,  privy  or  nuisance,  shall 
be  provided  with  a  sufficient  number  of  proper  water  closets,  earth  closets, 
or  privies,  and  shall  be  ventilated  in  such  a  manner  that  the  air  shall  not 
become  so  impure  as  to  be  injurious  to  health.  The  provisions  of  this 
section  shall  be  enforced  by  the  inspection  department  of  the  district  police. 

SECTION  55.  If  it  appears  to  an  inspector  of  factories  and  public  buildings 
that  further  or  different  sanitary  or  ventilating  provisions  which  can  be  pro~ 


6  THE    SCHOOL    HOUSE. 

vided  without  unreasonable  expense,  are  required  in  any  public  building  or 
school  house,  he  may  issue  a  written  order  to  the  proper  person  or  authority, 
directing  such  sanitary  or  ventilating  provisions  to  be  provided.  A  school 
committee,  public  officer  or  person  who  has  charge  of,  owns  or  leases  any 
such  public  building  or  school  house  who  neglects  for  four  weeks  to  comply 
with  the  order  of  such  inspector  shall  be  punished  by  a  fine  of  not  more  than 
one  hundred  dollars.  Whoever  is  aggrieved  by  the  order  of  an  inspector 
issued  as  above  provided  and  relating  to  a  public  building  or  school  house 
may,  within  thirty  days  after  the  date  of  the  service  thereof,  apply  in  writing 
to  the  board  of  health  of  the  city  or  town  to  set  aside  or  amend  the  order  ; 
and  thereupon,  the  board,  after  notice  to  all  parties  interested,  shall  give  a 
hearing  upon  such  order,  and  may  alter,  annul  or  affirm  it. 


After  the  committee  have  decided  upon  the  plan  preferred,  they 
can  then  report  to  the  city  or  town  and  ask  for  an  appropriation 
sufficient  to  properly  construct  the  building. 

The  appropriation  should  be  sufficient  to  cover  the  entire  cost  of 
the  site,  building,  furnishing,  grading  and  the  architect's  fee,  also 
a  reasonable  allowance  for  contingencies.  By  this  method  addi- 
tional appropriations  are  avoided,  and  the  committee  and  architect 
are  not  obliged  to  revise  the  plans  and  omit  essential  things  in 
order  to  keep  within  the  appropriation. 

The  appropriation  having  been  made,  the  committee  should  be 
authorized  to  contract  for  the  building. 

If  architects,  before  making  the  finished  drawings,  or  committees, 
before  accepting  them,  would  (in  Massachusetts)  submit  them  to 
the  State  Inspector  for  the  district,  the  inspector  will  inform  them 
as  to  whether  or  not  the  plans  meet  the  requirements  of  law  and 
will  be  approved. 

Sometimes  a  committee  will  accept  plans  that  the  inspector  can- 
not approve,  and  changes  will  be  ordered  which  may  increase  the 
cost  after  the  appropriation  is  made,  or  will  allow  the  contractor  to 
present  a  bill  for  u  extras."  u  Be  sure  you  are  right  and  then  go 
ahead." 

In  deciding  upon  competitive  plans  committees  are  often  pleased 
with  a  well-drawn  and  colored  elevation  or  perspective,  and  some- 
times lose  sight  of  the  more  important  interior  arrangement  of  the 
rooms,  etc. 

SITE. 

In  deciding  upon  the  choice  of  a  site  for  a  schoolhouse  many 
different  questions  will  arise  :  as  to  where  it  should  be  located  to 
be  near  the  central  part  of  the  district,  the  cost  of  the  land,  the 
nature  of  the  soil,  and  the  objectionable  surroundings  to  be  avoided. 


TY 

THE    SCHOOL   HOUSE.  7 

A  site  on  high,  dry  land  where  a  good  foundation  and  good 
drainage  or  sewerage  can  be  had  should  be  selected  if  possible. 

If  low  or  filled  land  must  be  used,  care  should  be  taken  that  good 
foundations  are  provided  and  supported  by  well-driven  piling,  if 
necessary ;  also  that  the  walls  and  bottom  of  the  basement  are  well, 
protected  and  made  water-tight  by  asphalt  or  hydraulic  cement. 

If  the  schoolhouse  is  to  be  built  on  clay  or  on  land  containing 
springs  of  water,  proper  precautions  should  be  taken  to  provide 
suitable  drainage  by  a  trench  outside,  filled  with  small  stones,  or 
by  drain-tile  placed  outside  to  carry  off  the  water. 

When  any  doubt  exists  as  to  the  nature  of  the  ground  it  is  advis- 
able that  borings  be  made  to  determine  whether  there  are  quick- 
sands, springs,  or  unstable  places,  also  as  to  whether  ledges  are  to 
be  found  in  excavating.  By  doing  this  the  architect  and  con- 
tractors will  be  enabled  to  make  a  better  estimate  of  the  cost,  and 
bills  for  "  extras"  are  often  avoided. 

A  site  should  be  selected  where  a  good  light  can  be  had  on  all 
sides  of  the  building,  and  unobstructed  by  trees  or  high  buildings. 
High  buildings  or  trees  close  to  a  schoolhouse  often  prove  serious  ob- 
stacles to  good  ventilation  on  account  of  deflection  of  the  wind,  which 
sometimes  causes  reversed  drafts  in  chimneys  and  ventilating  flues. 

It  is  not  desirable  to  place  the  schoolhouse  where  it  is  much 
exposed  to  very  high  winds. 

The  building  should  be  set  well  back  from  the  street  and  ample 
yard  room  provided. 

Close  proximity  to  manufacturing  establishments,  where  much 
smoke  or  noxious  gases  are  produced,  should  be  carefully  avoided, 
as  well  as  a  noisy  location,  where  pupils  and  teachers  are  annoyed 
and  their  attention  diverted  from  school  work. 

THE  BUILDING. 

School  buildings  should  be  plain,  and  substantially  built. 

The  money  frequently  expended  in  the  construction  of  towers, 
cupolas,  and  other  ornamentation,  can  be  used  to  much  better 
advantage  in  substantial  construction  and  convenient  interior 
arrangements. 

Not  that  a  building  should  be  hideously  plain ;  but  a  well 
proportioned  building,  with  simple  and  inexpensive  ornamentation, 
can  easily  be  designed  by  an  experienced  architect. 

A  schoolhouse,  two  stories  in  height,  and,  in  large  buildings, 
with  an  assembly  hall  above  the  second  story,  is  to  be  preferred  to 
one  of  three  or  four  stories. 


8  THE    SCHOOL   HOUSE. 

In  case  of  fire  or  panic  the  danger  is  greatly  increased  in  high 
buildings. 

Climbing  many  flights  of  stairs,  especially  for  girls,  is  not 
recommended. 

In  cities  where  land  is  very  valuable  it  sometimes  becomes 
necessary  to  have, the  school  building  more  than  two  stories  high; 
but  where  land  can  be  obtained  at  a  reasonable  price  two  stories 
are  preferable. 

CONSTRUCTION. 

When  a  sufficient  appropriation  can  be 'obtained  it  is  preferable 
that  the  building  be  of  fire-proof,  or  at  least,  slow-burning 
construction. 

After  the  first  cost  the  expenditure  for  repairs  is  much  less  for 
brick  than  for  wooden  buildings. 

If  wooden  construction  is  adopted  on  account  of  the  first  cost, 
care  should  be  taken  that  the  material  is  of  good  quality,  the 
timber  of  sufficient  size,  and  the  boarding  well  protected  with  a 
covering  of  the  best  quality  of  building  paper. 

A  loosely-constructed  building  requires  in  cold  weather  a 
constant  additional  expenditure  for  fuel  to  maintain  a  comfortable 
temperature  in  the  schoolrooms.  This  additional  expense  can  be 
considerably  reduced  by  good  construction  in  the  first  place. 

Particular  attention  should  be  given  to  have  all  trusses  properly 
designed,  placed,  and  of  sufficient  strength. 

The  writer  has  found  more  well-founded  complaints  of  insuffi- 
cient trussing  and  defective  roof-framing  than  from  any  other 
cause  (exclusive  of  heating  and  ventilation)  in  schoolhouse 
construction. 

It  is  too  often  the  case  that  architects  are  obliged  to  cut  down 
the  thickness  of  walls  and  partitions  and  reduce  the  size  and 
quality  of  the  timber  because  a  building  committee  insists  on 
having  a  large  building  for  little  money.  This  is  false  economy, 
as  will  be  apparent  after  the  building  is  occupied.  Better  reduce 
the  size  of  the  building  than. cut  down  the  material. 

In  brick  schoolhouses  an  air  space  in  the  walls  is  advisable,  and 
the  inner  walls  should  be  of  hard-burned  brick  with  terra-cotta  set 
to  receive  nailing  for  the  finish. 

The  wood  finish  should  be  reduced  to  the  minimum,  and  the 
walls  smooth  plastered. 

In  the  better  class  of  buildings  Windsor  or  equally  good  cement 
can  be  advantageously  used  for  door  and  window  trims.  Dados  of 
gauged  mortar  and  wood  base  are  also  used. 


THE    SCHOOL   HOUSE.  9 

Oak  or  ash  finish  is  preferable  to  white  pine  or  whitewood, 
which  are  too  soft  and  easily  defaced.  Cypress  is  sometimes  used, 
and  in  the  cheapest  buildings  Southern  pine  is  frequently  used. 

Expanded  metal  is  much  better  than  wooden  lathing.  Stamped 
metal  ceilings  are  sometimes  used,  but  the  advantage  is  not  great 
when  the  extra  cost  is  taken  into  account. 

In  some  cases  in  brick  school  buildings  the  wood  finish  in  the 
corridors  is  omitted  and  faced  brick,  carefully  laid,  and  painted 
with  a  light-colored  gloss  paint,  is  substituted.  This  has  proved 
quite  satisfactory. 

The  upper  floor-boards  should  be  of  rift  Georgia  or  Florida  pine, 
or  of  maple,  and  not  over  four  inches  wide.  Between  the  upper 
and  lower  floor-boarding  should  be  laid  asbestos  or  other  fire 
resisting  paper  or  material. 

MEANS  TO  PREVENT  SPREAD  OF  FIRE. 

The  following  are  the  requirements  of  the  Massachusetts  State 
Inspectors  for  buildings  other  than  in  the  city  of  Boston  : 

General  Specifications  for  Means  of  preventing  Spread  of  Fire  in  Buildings, 
under  the  Requirements  of  Chapter  104  of  the  Revised  Laws,  as  directed 
by  the  State  Inspectors  of  Factories  and  Public  Buildings.  Special  Provi- 
sions against  Spread  of  Fire,  required  in  Theatres,  are  not  included  in 
those  Specifications. 

1.  All  elevator  wells  and  light  shafts,  unless  built  of  brick,  must  be  filled 
in  flush  between  the  wooden  studs  with  fire-proof  materials  and  lined  with 
metal  or  plastered  on  metallic  lathing,  as  may  be  directed  by  the  inspector, 
and  all  wood-work   inside  of   such  wells  or  shafts,  be   lined  with  tin  plate, 
lock-jointed. 

2.  Where  floor  beams  rest  on  partition  caps  or  on  girders,  wall  girts,  or 
on  wooden  sills,  fill  in  between  such  beams,  from  the  caps,  girders,  girts  or 
sills,  to  four  inches  above  the  plaster  ground  solid  with  brick  and  mortar  or 
other  fire-proof  material. 

3.  When  floor  beams  in  frame  buildings  rest  on  ledger  boards,  fire-stop 
thoroughly  at  each  floor  with  brick  and  mortar  resting  on  bridging  pieces  cut 
in  between  the  studs,  or,  where  practicable,  on  the  ends  of  lining  floor. 

4.  In  brick  buildings  the  space  between  the  furrings  on  the  outside  walls 
or  on  brick  partitions  should  be  filled  flush  with  mortar  for  a  space  of  five 
inches  in  width  above  and  below  the  floor  beams  of  each  story. 

5.  Where  basement  or  other  flights  of  stairs  are  enclosed  by  partitions  of 
brick  or  wood,  the  spaces  between  the  studs  or  wall  furrings  must  be  so  fire- 
stopped  with  brick  or  mortar  as  to  effectually  prevent  any  fire  from  passing 
up  between  such  studs  or  furrings  back  of  the  stair  stringers. 

6.  The  soffits  of  all  such  enclosed  stairs,  and  also  partitions  on  stairway 
side,  must  be  plastered  on  metal  lathing. 

7.  Where  a  building  is  occupied  above   the  first   floor  for  any  purpose 
which  renders  it  subject  to  the  provisions  of  section  22  of  chapter  104  of  the 


10  THE    SCHOOL   HOUSE. 

Revised  Laws,  and  the  lower  story  is  occupied  for  stores,  or  other  purposes 
not  connected  with  the  upper  floors,  the  stairways  leading  to  such  upper 
floors  must  be  enclosed  with  brick  walls  or  with  wooden  partitions  filled 
solid  with  brick  laid  in  mortar,  or  other  fire-proof  material,  and  plastered  on 
both  sides  on  metallic  lathing,  and  all  doors  in  such  partitions  lined  with  tin 
plate,  lock-jointed. 

8.  All  long  flights  of  stairs  to  have  smoke  stops  in  each  flight,  properly 
constructed. 

9.  No  pipes  for  conveying  hot  air  or  steam  can  under  the  law  be  placed 
nearer  than  one  inch  to  any  wood-work  unless  protected  to  the  satisfaction 
of  the  inspector  by  suitable  guards  or  casings  of  incombustible  material. 

10.  No  wooden  flue  or  air-duct  of  any  description  can  be  used  for  heating 
or  ventilating  purposes. 

11.  A  space  of  at  least  one  inch  to  be  left  between  all  wood-work  and  the 
chimneys,  also  around  all  hot-air,  steam  and  hot-water  pipes ;  these  spaces 
around  chimneys  and  pipes,  where  they  pass  through  floors,  to  be  stopped 
with  metal  or  other  fire-proof  material,  smoke-tight.     Steam  and  hot-water 
pipes  to  have  metal  sleeves  and  collars. 

All  channels  and  pockets  for  gas,  water  and  soil-pipes  to  be  made  smoke- 
tight  at  each  floor. 

12.  The  space  around  all  metal  or  brick  ventilating  ducts  must  be  fire- 
stopped  at  each  floor  with  metal  or  other  fire-proof  material,  as  approved  by 
the  inspector. 

13.  All  chimneys  to  be  plastered  with  one  good  coat  of  brown  mortar,  on 
the  outside  of  brick-work,  from  cellars  to  roof. 

14.  The  ceiling  of  furnace  or  boiler  and  indirect  radiator  rooms  must  b£ 
plastered  on  metal  lathing.     There  should  be  not  less  than  one  foot  in  height 
of  open  air  space  between  the  tops  of  furnace  or  boiler  casing  or  any  smoke- 
pipe  and  the  ceiling. 

15.  The  entire  cellar  ceilings  of  schoolhouses  and  other  buildings  used 
for  public  purposes  must  be  plastered  on  metallic  lathing. 

So  much  of  these  specifications  as  applies  to  any  building  should  be  incor- 
porated by  the  architect  in  his  specifications  for  said  building,  and  the  clauses 
therein  incorporated  should  be  indicated  by  their  numbers  in  the  specification 
filed  with  the  inspector. 

These  specifications  are  to  be  followed  in  every  building  subject  to  the 
provisions  of  section  22  of  chapter  104  of  the  Revised  Laws,  unless  omitted 
or  changed  in  some  part  by  special  consent  of  the  inspector. 

Other  provisions  than  those  herein  specified,  to  prevent  spread  of  fire,  may 
be  required  by  the  inspector  if  deemed  by  him  to  be  necessary. 

MEANS  TO  EXTINGUISH  FIRE. 

Chapter  104  of  the  Revised  Laws  of  Massachusetts  requires  that 
means  to  extinguish  fire  be  provided  in  certain  buildings,  as  fol- 
lows : 

SECTION  25.  A  building  which  is  used,  in  whole  or  in  part,  as  a  public 
building,  public  or  private  institution,  school  house,  church,  theatre,  public 
hall,  place  of  assemblage  or  place  of  public  resort, 


THE    SCHOOL   HOUSE.  11 

SECTION  26.  Each  story  above  the  second  story  of  a  building  which  is 
subject  to  the  provisions  of  the  preceding  section  shall  be  supplied  with 
means  of  extinguishing  fire,  consisting  of  pails  of  water  or  other  portable 
apparatus  or  of  a  hose  attached  to  a  suitable  water  supply  and  capable  of 
reaching  any  part  of  such  story ;  and  such  appliances  shall  be  kept  at  all 
times  ready  for  use  and  in  good  condition. 

Although  not  required  by  the  Massachusetts  laws,  it  is  advisable 
that  each  story,  including  the  basement,  should  be  provided  with  a 
chemical  fire-extinguisher,  or  a  stand-pipe  and  hose  not  less  than 
two  inches  in  diameter.  Suitable  and  neat  hose  racks  should  also 
be  provided  in  the  corridors. 

In  order  that  the  stand-pipe  may  be  tested  to  see  if  it  is  full  of 
water,  and  to  do  this  without  wetting  the  hose,  it  is  advisable  to 
place  in  the  stand-pipe,  just  below  the  valve  in  each  story,  a  small 
try-cock.  Care  should  be  taken  that  the  connection  with  the 
street  water  main  is  not  less  in  diameter  than  that  of  the  stand- 
pipe  in  the  building. 

BASEMENT. 

The  basement  should  not  be  less  than  ten  feet  high  and  twelve 
feet  is  preferable. 

It  should  be  well  lighted,  and  when  practicable,  at  least  five 
feet  should  be  above  ground. 

The  basement  floor  should  be  of  concrete,  not  less  than  four 
inches  thick,  with  a  well-smoothed  covering  of  three-quarters  of 
an  inch  thick  of  rock  asphalt  or  Portland  cement.  Rosendale  or 
similar  cement  is  unsuitable  for  the  top  covering  of  a  schoolhouse 
basement  on  account  of  being  easily  worn  and  broken  by  the 
pupils.  When  so  used  there  is  complaint  of  the  dust  arising  from 
the  fine  detached  particles  of  cement. 

On  wet,  filled  or  clayey  ground  it  is  advisable  to  cover  the 
outside  of  the  foundation  and  bottom  of  the  basement  concrete 
floor  with  boiled  asphalt  to  prevent  moisture  or  earth  exhalations 
from  entering  the  building. 

The  floor  of  the  boiler,  furnace  and  coal  rooms  should  be  paved 
with  brick,  preferably  set  on  edge  in  cement  mortar. 

The  floor  of  the  sanitary  and  playrooms  should  be  graded  to 
some  convenient  point,  at  which  a  drain  with  a  perforated  cover  is 
placed,  in  order  that  the  floor  may  be  thoroughly  washed  by  water 
from  a  hose. 

The  drain  for  this  purpose  should  be  well  trapped  and  not 
connected  with  the  drain  from  the  sanitary  fixtures. 

The  heating  apparatus,  cold-air  rooms,  sanitary,  play  and  lunch- 


12  THE    SCHOOL   HOUSE. 

rooms  should  be  in  the  basement,  and  when  a  manual  training  room 
or  gymnasium  is  there,  the  wood  floor  should  be  laid  on  screeds 
embedded  in  concrete,  and  the  space  between  the  screeds  filled 
with  cement  or  cinder  concrete. 

A  chemical  laboratory  should  never  be  placed  in  the  basement. 

The  flooring  of  the  rooms  over  the  cold-air  room  should  be  well 
protected  by  some  non-conducting  material  to  prevent  the  cold 
from  striking  up  through  the  floor  of  the  first  story. 

This  is  sometimes  done  at  a  moderate  expense  by  fastening  two 
or  more  thicknesses  of  building  or  thick  asbestos  paper  between 
the  floor  timbers,  about  half-way  between  the  metallic  lathing  and 
the  floor  boarding,  holding  it  in  place  by  strips  of  furring  nailed  to 
the  sides  of  the  floor-beams. 

A  bicycle  run  and  stalls  or  racks  should  also  be  provided. 

Galvanized  iron  ash-holders  should  be  provided  for  removing 
the  ashes  from  the  boiler  or  furnace  room,  also  a  convenient  ash- 
lift  or  door. 

Suitable  soapstone  or  iron  sinks,  drinking-cups  and  wash-basins 
should  be  provided  in  the  play-rooms ;  also  in  the  boiler  or  furnace- 
room  for  the  use  of  the  janitor  or  engineer. 

Where  practicable,  a  janitor's  room  and  work-bench  should  be 
provided. 

Hose  and  pipe  should  also  be  provided  for  washing. 

Danger  from  fire  is  greater  in  the  basement  than  in  other  parts 
of  the  building,  and  as  little  wood  finish  should  be  used  there 
as  possible. 

It  is  advisable  that  the  boiler  or  furnace  rooms  should  be  fire- 
proof;  or,  at  least,  of  slow  burning  construction,  and  that  metal- 
covered  doors  be  used  for  these  rooms. 

The  basement  stairways  should  be  shut  off  from  the  corridors  by 
doors  to  prevent  smoke  from  rapidly  filling  the  corridors  and 
upper  stairways. 

Closets  should  not  be  allowed  under  stairways,  as  they  frequently 
become  receptacles  for  inflammable  material,  such  as  waste  paper, 
oil-cans,  etc. 

CORRIDORS. 

Corridors  should  be  wide  and  well  lighted.  Twelve  feet  is  not 
too  wide,  and  when  the  outer  garments  of  the  pupils  are  hung 
there  fifteen  feet  is  to  be  preferred. 

In  small  schoolhouses  the  outer  garments  can  be  hung  there, 
either  on  wall  supports,  or  in  stalls  preferably  made  of  wire  grill 
work  of  about  one-eighth  inch  diameter  wire,  and  about  two  inches 


THE   SCHOOL   HOUSE.  13 

diamond  mesh.  This  gives  a  much  better  chance  for  the  air  to 
circulate  than  when  wood  partitions  are  used,  and  the  pupils,  when 
the  wire  grill  work  is  used,  can  be  kept  in  view  of  the  teachers. 
The  top  of  the  grill  work  is  usually  from  five  to  six  feet,  and  the 
bottom  about  one  foot  above  the  floor. 

A  shelf  of  wire  grill,  on  which  to  place  overshoes,  is  often  put 
at  the  bottom  of  the  upright  grill.  In  some  cases  another  shelf  is 
placed  near  the  top.  Hat  and  coat  hooks  in  primary  schools  are 
placed  four  feet  above  the  floor,  and  in  other  schools  five  feet. 
Thirty  running  feet  for  a  fifty  seat  room  is  usually  the  minimum 
hanging  space. 

It  is  advisable  to  run  two  lines  of  one  and  one-quarter  inch 
steam  pipe  a  short  distance  above  the  floor  and  under  the  clothing, 
for  the  purpose  of  drying  in  stormy  weather. 

Where  practicable,  umbrella  racks  are  advisable. 

All  corridors  and  clothing  rooms  should  be  well  ventilated ;  but 
it  is  not  requisite  that  a  separate  air  supply  should  be  provided,  as 
the  leakage  of  outside  air  and  the  frequent  opening  of  outside  doors 
will  generally  furnish  the  required  amount  of  fresh  air.  A  good 
exhaust  duct  is,  however,  necessary. 

"  Foot- warmers  "  should  be  in  all  cases  provided  in  the  lower 
corridor,  in  order  that  in  cold  or  stormy  weather  the  pupils  may  be 
provided  with  means  for  drying  and  warming  their  clothing  and 
feet.  The  air  supply  for  the  foot  warmers  may  be  taken  in  through 
the  risers  in  the  vestibule  stairs,  or  it  may  be  rotated  from  the 
corridor. 

In  large  buildings,  or  where  the  cost  does  not  prevent,  separate 
coat  rooms  may  be  provided. 

E.  M.  Wheelwright,  in  his  excellent  work  on  schoolhouse  archi- 
tecture, says,  "  specially  designed  separate  clothing  rooms  add 
about  from  four  to  four  and  one-half  per  cent  to  the  cost  of  the 
building." 

A  hand  bowl  and  faucet  or  drinking  fountain  should  be  provided 
in  each  corridor,  and  in  some  cases  a  mirror,  soap  and  towels  are 
added. 

Glass  panels  in  the  class-room  doors  assist  materially  in  lighting 
the  corridors  and  enable  the  teachers  to  observe  what  is  passing 
there.  Transoms  over  the  doors  are  also  desirable. 

In  some  buildings,  where  long  and  difficultly  lighted  corridors 
are  designed,  small  windows  near  the  ceiling  of  the  class-rooms 
have  been  used  to  good  advantage  to  assist  in  lighting  the  corridors. 


14  THE    SCHOOL   HOUSE. 

VESTIBULES. 

Vestibules  are  desirable  for  all  schoolhouses.  They  should  be 
well  lighted  and  have  self-closing  doors. 

In  cold  and  stormy  weather,  where  no  vestibules  are  provided 
the  corridors  and  other  parts  of  the  building  are  often  very  rapidly 
cooled,  especially  before  the  session  or  during  recess,  by  opening 
outside  doors  directly  into  the  corridor. 

In  the  matter  of  economy  of  fuel,  if  for  no  other  reason,  vesti- 
bules should  always  be  provided  in  schoolhouses. 

If  it  is  not  practicable  to  construct  a  vestibule,  a  temporary  out- 
side storm  porch  should  be  constructed  of  matched  boards  for  use 
in  winter,  and  capable  of  being  removed  for  warm  weather. 

EXITS. 

There  should  be  at  least  two  ways  of  exit  from  every 
schoolhouse. 

The  stairways  and  outside  doors  should  be  placed  as  far  apart  as 
practicable  and  should  be  not  less  than  four  feet  wide.  Five  feet 
is  better. 

The  Massachusetts  inspectors  require  means  of  exit  equal  to 
twenty  inches  for  each  one  hundred  persons  accommodated  in  a 
public  building;  but  no  stairway  to  be  less  than  four  feet  wide 
in  the  clear.  (For  theaters  the  law  requires  forty  inches  for  each 
100  persons,  and  no  exit  to  be  less  than  five  feet  wide.) 

When  the  expense  can  be  incurred  it  is  desirable  that  stairways 
in  brick  school-buildings  be  made  fire-proof  and  enclosed  in  brick 
walls.  'The  stairs  should  be  of  iron,  and  in  the  treads  should  be 
embedded  safety  treads,  not  less  than  five  and  one-half  inches 
wide,  and  made  of  a  combination  of  steel  and  soft  metal,  or 
rubber  covering  can  be  advantageously  used. 

In  wooden  buildings  the  sides  of  the  stair-stringers  should  have 
the  spaces  between  the  studs  or  wall-furrmgs  so  stopped  with 
brick  or  mortar  as  to  effectually  prevent  fire  from  passing  up 
between  the  studs  or  furrings  back  of  the  stair-stringers,  and  the 
soffits  of  enclosed  stairs,  and  the  partitions  on  the  stairway-side 
should  be  plastered  on  expanded  metal  lathing.  At  least  two 
cut-offs  or  fire  stops  should  be  put  in  each  stairway. 

Enclosed  stairwaysf  should  have  a  substantial  hand-rail  on  each  side. 

Open  stairways  should  have  a  hand-rail  on  the  wall  side,  and 
especial  care  should  be  taken  that  the  outer  posts  and  balusters  are 
strong  enough  to  prevent  being  broken  or  pushed  out  of  place 
should  the  stairway  become  overcrowded  in  case  of  panic. 


THE    SCHOOL   HOUSE.  15 

Circular  stairways  or  winders  should  never  be  placed  in  school- 
houses  or  places  of  assemblage. 

In  the  lower  grade  schools,  risers  should  preferably  be  six  inches 
with  twelve-inch  tread ;  in  other  grades,  risers  not  more  than  seven 
inches,  with  ten  and  ^one-half  inches  tread. 

The  product  of  the  rise  and  run  should  not  be  less  than  severity 
or  more  than  seventy-five. 

'There  should  not  be  less  than  two,  nor  more  than  fifteen  steps 
between  landings,  and  landings  not  less  than  four  feet  long. 

The  ordinary  jire-escape,  such  as  is  zised  on  factories,  hotels, 
tenement-houses,  etc.,  should  never  be  placed  on  a  school-building 
unless  it  is  impossible  to  pro-vide  other  ways  of  exit. 

The  danger  would  be  very  great  if  in  case  of  fire  an  attempt 
should  be  made  to  have  a  large  number  of  children  go  down  the 
narrow  fire-escapes  of  the  ordinary  design. 

The  pupils  would  be  very  likely  to  become  frightened  when  they 
looked  down  from  the  open  fire-escape,  would  hesitate,  stop,  and 
be  pushed  by  those  in  the  rear,  and  a  panic  would  ensue. 

The  writer  has  not  for  many  years  required  the  ordinary  fire- 
escape  to  be  placed  on  any  schoolhouse.  When  additional  means 
of  exit  from  a  schoolhouse  must  be  provided,  it  should  be  by 
enclosed  stairways  with  hand-rails  on  each  side. 

Outside  main  entrance  and  vestibule  doors  should  open  out  or 
both  ways. 

The  standing  leaf  of  all  pairs  of  doors  leading  to  ways  of  egress 
should  be  fastened  by  face  T-bolts,  operated  at  top  and  bottom  by 
one  handle  placed  at  a  convenient  height  from  the  floor. 

Edge  bolts  should  not  be  used,  on  account  of  the  difficulty  of 
opening  quickly. 

Schoolhouse  doors  should  never  be  fastened  during  school  hours 
in  a  manner  that  will  prevent  them  being  quickly  opened  from  the 
inside.  If  desirable  to  prevent  persons  from  entering  the  building, 
the  door-knobs  may  be  arranged  to  open  the  door  from  the  inside, 
but  not  from  the  outside.  An  electric  bell  should  be  provided  for 
the  use  of  persons  desiring  to  enter. 

Doors  used  as  exits  from  the  building  should  be  at  least  equal  in 
width  to  the  stairways. 

No  door  opening  inward  at  the  bottom  of  any  stairway  should  be 
allowed  in  any  pulflic  building. 

Door-checks  for  outside  doors  will  soon  save  the  additional  cost 
in  the  amount  of  fuel  burned  in  cold  weather. 

\ 


16  THE    SCHOOL   HOUSE. 

From  each  class-room  at  least  one  door  should  open  out,  and 
class-rooms  on  the  same  story  or  side  of  the  corridor  should  have 
connecting  doors. 

WINDOWS. 

Windows  in  class-rooms  should  preferably  be  four  feet  between 
jambs,  three  feet  above  the  floor,  and  about  six  inches,  or  only 
enough  for  the  finish,  from  the  top  to  the  ceiling. 

Four  lights  of  glass  in  each  window  is  a  desirable  number. 

Three  windows  at  the  rear  and  four  at  the  left  of  the  pupils  give 
a  very  good  light  for  the  ordinary  sized  school-room,  lighted  from 
two  sides. 

When  only  lighted  from  the  left  of  the  pupils'  desks,  five 
windows  are  preferable  if  the  construction  of  the  building  will 
allow  it. 

Arched  windows  are  objectionable  in  a  class-room. 

Transoms  may  be  allowed  for  summer  ventilation  where  a  gravity 
system  is  used ;  but  double  windows  are  more  desirable,  especially 
on  the  sides  most  exposed  to  the  prevailing  winter  winds.  A  very 
considerable  saving  of  fuel  is  made  by  their  use,  and  they  also  to  a 
large  extent  prevent  the  cold  drafts  caused  by  the  rapid  cooling  of 
the  air  on  the  glass  surface. 

Double-glazed  sash,  that  is,  two  lights  of  glass  set  with  about 
one-half-inch  air  space  between  them,  is  sometimes  used  to  good 
advantage,  but  is  'not  as  desirable  as  double  run  of  sash. 

When  double  glazing  is  used  care  should  be  taken  that  the  glass 
is  thoroughly  cleaned  and  dried  before  setting. 

When  either  the  gravity  or  mechanical  system  of  ventilation  is 
in  use  all  windows,  transoms  and  doors  in  class-rooms  should  be 
closed  in  order  to  obtain  the  best  results. 

Windows  should  have  an  eye  or  a  depressed  piece  of  metal  set 
into  the  upper  part  of  the  sash,  by  means  of  which  they  can  be 
easily  lowered  or  raised  with  a  window  pole  or  rod. 

Transoms  should  be  hung  at  the  bottom  and  opened  or  closed  by 
adjusting  rods. 

Class-room  doors  opening  into  a  corridor  should  have  a  large 
light  of  heavy  glass  set  in  the  center  and  about  four  feet  above  the 
floor/ 

Windows  grouped  as  mullions  do  not  give  as  satisfactory  light 
as  when  equally  spaced  in  the  outer  wall. 

Basement  windows  should  when  practicable  be  about  four  feet 
high  and  correspond  in  width  to  those  in  the  stories  above. 


THE    SCHOOL    HOUSE.  17 

Care  should  be  exercised  that  all  spaces  about  the  window  frames 
are  caulked  or  made  as  tight  as  possible.  Neglect  of  this  precau- 
tion is  often  a  cause  of  complaint  of  uncomfortable  drafts. 

Venetian  or  other  blinds  are  very  objectionable  in  school  rooms. 

Roller  shade  curtains,  which  can  be  adjusted  to  raise  or  lower 
from  either  the  top  or  bottom,  by  means  of  a  slide  or  a  rod  at  each 
side  of  the  window,  and  operated  by  a  cord  to  hold  the  curtain  in 
any  position,  are  very  desirable,  and  enable  the  teacher  to  regulate 
the  light  in  a  satisfactory  manner. 

Many  of  the  modern  school  buildings  are  now  provided  with 
these  adjustable  curtains. 

They  assist  in  partly  solving  the  much-discussed  problem  of  using 
light  from  the  north  or  other  points  of  the  compass. 

Much  has  been  written  regarding  the  amount  of  light  admitted 
to  a  schoolroom,  and  from  which  point  of  the  compass  it  should 
come. 

To  carry  out  the  theories  of  some  writers  would  require  the  class- 
rooms to  be  of  a  height  that  would  very  materially  increase  the  cost 
of  the  building. 

By  having  a  sufficient  number  of  wide  windows  which  extend 
nearly  to  the  ceiling,  and  by  the  judicious  use  of  properly  colored 
adjustable  curtains,  many  of  the  objections  can  be  in  a  great 
measure  overcome. 

The  theory  that  only  a  north  light  should  be  used  in  a  school- 
room will  often  lead  to  objectionable  conditions  in  the  heating  and 
ventilation. 

Where  a  corridor  is  located  north  or  northwest  from  class-rooms 
a  more  even  temperature  and  better  circulation  of  air  is  obtained 
than  where  the  class-rooms  are  exposed  to  the  prevailing  winds, 
which  in  Massachusetts  are  from  the  northwest  and  north  in  the 
winter. 

CLASS-ROOMS. 

The  standard  generally  adopted  for  a  class-room  in  Massachu- 
setts, for  what  is  usually  called  a  fifty  seat  room,  is  32  feet  long, 
28  feet  wide  and  12  feet  high. 

In  the  lower  grades  sometimes  56  seats  are  provided,  but  this 
large  number  is  not  recommended. 

Grammar  and  the  high  grade  rooms  are  commonly  seated  for 
42,  47,  48  or  49  pupils. 

Twenty-eight  by  thirty-two  feet  gives  a  floor  space  of  896  square 
feet,  and  allows  21.33  square  feet  of  floor  space  for  42,  19.06  for 
47,  18.66  for  48,  and  18.28  for  49  pupils.  Allowing  one  teacher 


18  THE    SCHOOL   HOUSE. 

per  room  gives  respectively  20.83,  18.16,  18.28  and  17.92  square 
feet  of  floor  space  for  each  occupant. 

The  rooms  being  12  feet  high  gives  10,752  cubic  feet  of  air 
space.  This  space  includes  that  occupied  by  the  furniture  and 
persons  in  the  room.  Usually  this  is  not  taken  into  consideration, 
but  for  accurate  calculation  it  should  be. 

Allowing  42,  47,  48  and  49  pupils,  this  10,752  cubic  feet  of  air 
space  gives  respectively  256,  228.7,  224  and  219.42  per  pupil,  or, 
allowing  for  one  teacher,  we  have  250.04,  224,  219.42  and  215.44 
cubic  feet  of  air  space  per  person. 

For  approximate  calculation  we  may  estimate  an  ordinary  school- 
room in  Massachusetts  as  containing  10,000  cubic  feet  of  air  space. 

While  these  amounts  of  floor  and  air  space  do  not  quite  agree 
with  the  recommendations  of  a  number  of  writers,  yet  with  a 
properly  designed  system  of  heating  and  ventilation  30,  40  or  50 
cubic  feet  of  air  per  minute  may  be  supplied  to  each  occupant  with- 
out uncomfortable  drafts  being  perceived. 

With  wide  and  high  windows,  properly  located,  very  little  com- 
plaint can  reasonably  be  made  as  to  satisfactory  lighting.  At  least 
this  has  been  the  experience  of  the  writer  while  making  many  tests 
of  heating  and  ventilation,  and  in  many  conversations  with  teachers 
and  pupils. 

Twelve  feet  appears  to  be  a  desirable  height  for  ordinary  class- 
rooms where  the  inlets  and  outlets  for  ventilation  are  of  ample  size 
and  properly  located. 

This  height  will  allow  a  good  circulation  of  air,  while  a  lower 
stud  may  sometimes  cause  uncomfortable  drafts.  A  higher  stud 
than  12  feet  increases  the  cost  of  the  building  without  giving  an 
adequate  return. 

In  rooms  14  feet  high  the  circulation  of  air  is  no  better  than  in 

those  12  feet  high.  ^ 

SEATING. 

The  convenient  arrangement  of  seats  in  a  class-room  will  depend 
upon  the  number  of  pupils  to  be  accommodated. 

In  assembly  and  public  halls  (except  theaters)  the  Massachusetts 
inspectors  allow  six  square  feet  of  floor  space  for  each  person. 
This  includes  aisles,  and  the  open  spaces  in  front  of  the  stage  or 
platform  and  at  the  rear  of  the  seats. 

In  determining  the  width  of  exits  from  halls  or  places  of  assem- 
blage, divide  the  number  of  square  feet  of  floor  space  in  front  of  the 
stage  or  platform  by  six  for  the  seating  capacity.  The  width  of  the 


THE    SCHOOL    HOUSE.  19 

exits  is  determined  by  the  seating  capacity ;  allowing  20  inches  for 
each  100  persons;  but  no  exit  to  be  less  than  four  feet  wide. 

It  is  intended  that  the  audience  shall  pass  out  in  lines  20  inches 
wide ;  that  is,  200  persons  should  have  at  least  forty-eight  inches 
in  width  of  exit;  300,  sixty  inches;  400,  eighty  inches,  etc. 

Lecture-rooms  in  the  larger  schoolhouses  are  generally  seatetl  in 
amphitheatre  form,  and  seats  with  a  broad  arm  or  small  table- 
attachment  are  desirable  to  enable  the  pupils  to  conveniently  make 
notes  of  the  lecture. 

In  class-rooms  the  seats  should  be  arranged  in  a  manner  that 
will  allow  the  light  to  reach  the  pupils  from  the  left  and  rear  when 
the  room  is  lighted  on  two  sides,  and  from  the  left  when  the  light 
is  from  one  side  only. 

When  the  light  comes  from  the  right  the  effect  is  bad,  especially 
when  the  pupils  are  writing,  the  shadow  of  the  hand  being  very 
trying  to  the  eyes. 

Class-room  seats  should  never  be  placed  in  a  position  which 
requires  the  pupils  to  face  the  windows.  The  teacher,  not  being 
obliged  to  remain  in  one  position,  can  better  face  the  light  occa- 
sionally than  to  require  all  the  pupils  to  do  so  constantly. 

In  most  modern  schoolhouses  the  teacher's  platform  is  omitted, 
and  a  movable  desk  which  can  be  placed  in  any  desirable  position 
is  provided. 

The  ordinary  size  for  a  teacher's  desk  is  about  50  inches  long, 
30  inches  wide,  and  31  inches  high. 

.Seats  and  desks,  the  height  of  which  can  be  adjusted  to  the  size 
of  the  pupils,  are  much  better  than  those  which  require  pupils  of 
different  ages  and  height  to  have  the  same  size  desk  and  seat. 

There  are  several  styles  of  adjustable  seats  and  desks  in  the 
market,  and  money  expended  in  this  manner  is  well  invested  for 
the  health  and  comfort  of  the  pupils. 

The  seats  and  desks  should  be  adjusted  to  the  size  of  the  pupils 
at  least  as  often  as  the  beginning  of  each  school  term. 

The  old-fashioned  double  seats  and  desks  occupied  by  two  pupils 
should  not  be  tolerated  in  any  modern  class-room.  Seats  and  desks 
in  class-rooms  should  be  adjustable  in  order  that  they  may  be  fitted 
to  the  needs  of  each  individual  pupil. 

Ill-fitting  seats  and  desks  are  often  responsible  for  round 
shoulders,  spinal  curvature,  and  impaired  eyesight. 

There  are  measuring  gauges  by  means  of  which  the  height  of 
seats  and  desks  may  be  readily  adjusted. 


20 


THE   SCHOOL   HOUSE. 


The  following  show  samples  of  adjustable  and  other  kinds  of 
furniture  used  in  Massachusetts  schoolhouses. 


FIG   1. 


FIG.  2. 


FIG.  3. 


FIG.  4. 


Tablet 
Arm 


FIG.  5. 


FIGS.  6  AND  7. 


FIG.  8. 


THE    SCHOOL   HOUSE. 


21 


Side  aisles    are   usually  from   three  to   four  feet   wide.     Aisles 
between  desks  are  usually  18  inches,  but  vary  from  16  to  24  inches, 
according  to  size  of  the  room  and  the  number  and 
size  of  desks. 

In  high  schools  the  distance  between  row^qf 
desks  is  often  30  inches,  and  the  desk  tops  are  20 
by  26  inches. 

In  schoolhouses  having  a  room  for  the  principal 
or    head  master  there  will    generally  be  found  a 
roller-top  desk  for  his  use,  and  frequently  a  lounge 
and  extra  chairs  are  provided. 
A    carpet   and    some    appropriate    pictures    add   to   the   general 
appearance  of  the  room. 

The  following  sizes  may  be  considered  as  desirable  for  pupils  of 
different  ages  and  grades. 


FIG. 


• 

Dimensions 

Range  of  Height  of  Adjustment  in  Inches. 

Ages. 

Grades. 

of  Desk  Top 

in  Inches 

Chair. 

Desk. 

Age  of  Pupil. 

5  or    6  years 
6  or    7  years 

5} 

12  x  18 

9|  to  13£ 
10i  to  15 

17i  to  22k 
18    to  25 

4  to    8  years 
5  to  12  years 

7  or    8  years 
8  or    9  years 

n 

13  x  21 

124  to  17 

20£  to  29 

7  and  upwards 

9  or  10  years 

5 

10  or  11  years 

6 

16  x24 

131  to  18| 

23    to  31 

11  and  upwards 

11  or  12  years 

7    J 

12  or  13  years 

8 

18x24 

13  or  14  years 

9 

20  x26 

High-school   desks  are   usually    made  with  tops  either   18  x  24 
inches  or  20  x  26  inches. 


Dimensions  of 
Desk  Top. 

Space  Occupied. 

12 

x 

18 

inches 

1 

From 
From 

side  to  side,  18  inches 
front  of  desk  to  rear  of 

chair, 

25 

inches 

13 

x 

21 

inches 

{ 

From 
From 

side  to  side,  21  inches 
front  of  desk  to  rear  of 

chair, 

27 

inches 

16 

X 

24 

inches 

{ 

From 
Front 

side  to  side,  24  inches 
front  of  desk  to  rear  of 

chair, 

30 

inches 

18 

X 

24 

inches 

f 

From 
From 

side  to  side,  24  inches 
front  of  desk  to  rear  of 

chair, 

34 

inches 

20 

X 

26 

inches 

{ 

From 
From 

side  to  side,  26  inches 
front  of  desk  to  rear  of  chair, 

36 

inches 

Allow  one  inch  between  back  of  desk  and  back  of  chair.- 


22  THE    SCHOOL    HOUSE. 

BLACKBOARDS  . 

Class-room  blackboards  should  be  of  slate  and  set  on  the  two 
inner  walls.  Where  an  appropriation  will  allow,  all  available 
space  should  be  so  occupied.  Not  that  the  space  between  the 
windows  should  be  used  for  daily  exercises ;  but  exhibition  draw- 
ings or  artistic  designs  drawn  there,  add  much  to  the  general 
appearance  of  the  room. 

Blackboards  should  be  at  least  3  feet  high;  3  feet  6  inches  or 
even  4  feet  is  not  excessive  in  the  higher  grade  rooms. 

In  primary  schools  they  are  set  2  feet  4  inches,  and  the  other 
grades  3  feet  above  the  floor. 

A  chalk  and  eraser  receiver  2  %  inches  wide  should  be  set  below 
the  blackboard. 

In  lecture-rooms  sliding  blackboards  set  in  frames  that  will  allow 
two  or  more  boards  to  be  used  in  succession  are  advisable. 

CLOCKS,  THERMOMETERS  AND  PICTURES. 

A  clock  should  be  provided  in  each  class-room.  In  many  of 
the  larger  buildings  electric  clocks  connected  with  a  regulating  one 
in  the  head  master's  room  are  provided  in  the  several  class-rooms, 
and  indicate  the  time  for  various  recitations  or  change  of  classes. 

A  thermometer  should  also  be  placed  in  each  class  or  recitation 
room,  and  if  proper  attention  is  given  to  the  indicated  temperature 
more  satisfactory  results  will  be  obtained,  not  only  as  to  the  com- 
fort of  the  teacher  and  pupils,  but  a  considerable  saving  can  be 
made  in  fuel. 

It  is  advisable  to  place  the  thermometer  about  on  the  breathing 
line  of  the  pupils  when  in  their  seats,  and  to  hang  it  in  a  location 
where  it  will  be  but  little  acted  on  by  the  rays  of  the  sun,  or  by 
cold  outside  walls  or  drafts  from  windows  or  doors,  or  opposite  a 
warm-air  inlet. 

On  the  teacher's  desk  or  on  an  inside  wall  is  generally  the  best 
location. 

At  least  one  thermometer  should  be  placed  on  the  outside  of  the 
building  in  such  a  position  as  will  screen  it  as  much  as  possible 
from  the  direct  rays  of  the  sun.  This  will  be  of  service  to  the 
janitor  in  regulating  his  fires,  and  thereby  controlling  to  a  consid- 
erable extent  the  amount  of  fuel  used. 

Moulding  for  hanging  pictures  is  often  .provided  in  schoolrooms 
and  a  few  appropriate  pictures  add  much  to  the  general  appearance 
of  the  room. 


THE    SCHOOL'  HOUSE.  23 

In  many  of  the  large  school  buildings  appropriate  plaster  casts 
are  provided,  which  with 'artistic  pictures  in  various  parts  of  the 
building  present  a  fine  appearance  and  are  appreciated  by  teachers, 
pupils  and  visitors. 

In  many  of  the  large  school  buildings  provision  is  often  made_ 
for  additional  rooms :  for  an  assembly  hall,  manual  training, 
gymnasium,  chemical,  physical  and  biological  laboratories,  type- 
writing and  stenography,  business  course,  cooking,  lunch,  teachers, 
clothing,  sanitary,  emergency,  library,  and  a  janitor's  workroom ; 
also  book  cases  and  storage  closets. 

In  many  schoolhouses,  telephone  connection  is  provided  between 
the  class-rooms  and  for  the  janitor  and  the  principal's  room.  This 
is  more  desirable  than  speaking  tubes,  which  are,  however,  used 
to  a  considerable  extent. 

In  many  buildings  telephone  connection  is  provided  through  the 
"  central "  telephone  office  with  other  buildings  and  with  the 
superintendent  of  schools. 

Fire-alarm  boxes  are  often  placed  in.  or  near  schoolhouses  for 
use  in  case  of  emergency. 


CHAPTER  II. 


AIR. 

THE  atmospheric  air  we  breathe  consists  of  a  mechanical 
mixture  of  approximately  21  parts  of  oxygen  and  79 
parts  of  nitrogen,  and  usually  about  four  parts  of  carbonic 
acid  in  10,000  parts  of  air. 

A  large  number  of  analyses  taken  in  different  places  by  different 
persons  show  that  when  the  air  is  not  particularly  contaminated  by 
local  conditions  four  parts  of  carbonic  acid  gas  in  10,000  parts  of 
air  may  be  considered  a  fair  standard. 

A  number  of  other  substances  are  also  found  in  air,  such  as  ozone, 
watery  vapor  and  organic  matter  given  off  by  living  animals,  dust 
particles,  microbes,  ammonia  compounds,  sulphuretted  hydrogen, 
sulphurous  and  sulphuric  acid,  nitrous  and  nitric  acid,  carbonic 
oxide,  sewer  gas  and  many  substances  produced  by  various  sources 
of  contamination ;  also  some  30  species  of  moulds  and  yeasts, 
together  with  the  recently  discovered  argon  and  other  substances. 

In  breathing,  the  movements  of  respiration  follow  each  other  at 
the  rate  of  18  or  20  a  minute. 

Quetelet  gives  the  respirations  per  minute  at : 

Birth,  44 ;  five  years,  26  ;  from  15  to  20  years,  20  ;  from  20  to 
25  years,  18.7  ;  from  25  to  30  years,  16  ;  from  30  to  50  years,  18.1. 

Dr.  Edward  Smith  found  from  numerous  experiments  that  the 
average  depth  of  respiration  was  33.6  cubic  inches  when  at  rest. 

Different  authorities  give  the  amount  of  air  inspired  and  expired 
as  from  26  to  40  cubic  inches.  The  movements  of  respiration  are 
accelerated  by  muscular  action. 

When  the  lungs  have  been  emptied  by  expiratory  effort  they  still 

contain    in    the  smaller   bronchi  and    air    sacs    a  quantity  termed 

residual  air,  which  cannot  be  expelled,  and  which  is  estimated  by 

'different  authorities  as  from  40  to  100  cubic  inches.     A  fair  average 

may  be  taken  as  75  cubic  inches. 

Allowing  the  amount  of  air  inspired  and  expired  to  be  30  cubic 
inches  at  each  respiration,  and  20  respirations  per  minute,  makes  600 
cubic  inches  of  air,  or  .34  cubic  feet  of  air  actually  used  per  minute. 

The  air  inhaled  passes  through  the  lungs  and  is  deprived  of  a 
percentage  of  its  oxygen,  which  passes  into  the  blood,  where  it  is 


THE    SCHOOL    HOUSE.  25 

taken  up  by  the  tissues,  which  are  oxidized  and  carbonic  acid  gas 
and  other  impurities  are  taken  away  by  the  expired  air,  which,  on 
leaving  the  lungs,  contains  about  400  parts  of  carbonic  acid  instead 
of  the  four  parts  in  10,000  parts  of  air  when  inhaled. 

Oxygen  is  the  life-giving  element  of  the  atmosphere  and  is 
essential  for  the  support  of  life  and  also  combustion. 

In  the  human  body  there  are  constantly  going  on  chemical 
changes  which  may  be  compared  to  the  action  of  a  fire.  Acting 
upon  the  excess  of  carbon  and  other  ingredients  in  the  blood, 
chemical  compounds  are  formed  and  thrown  off  by  the  breath  of 
the  individual.  Thus  the  life-giving  element  of  the  air  is  reduced, 
and  poisonous  and  harmful  substances  are  introduced  in  its  place. 

The  nitrogen  is  practically  inert  in  the  process  of  respiration  and 
combustion,  and  is  not  affected  by  passing  through  the  lungs  or  a 
fire.  It  renders  the  oxygen  less  active  and  absorbs  some  of  the 
heat  produced. 

Carbonic  dioxide  (CO2),  or  carbonic  acid,  is  the  result  of 
combustion  of  carbon,  and  although  not  in  itself  considered  a 
poisonous  gas,  yet  it  may  cause  the  death  of  a  person  by  suffocation 
for  want  of  the  life-giving  oxygen. 

As  a  product  of  respiration  and  combustion,  carbonic  acid  is 
taken  as  an  indication  of  the  amount  of  other  impurities  present, 
and  should  not  exceed  eight  parts  in  10,000  in  air  intended  for 
breathing,  and  in  many  well-ventilated  buildings  it  is  often  found 
less  than  six  parts. 

Carbonic  oxide  (CO)  is  distinctly  a  poison,  and  has  a  character- 
istic reaction  on  the  blood.  Carbonic  oxide  is  doubly  dangerous, 
for,  like  carbonic  acid  it  is  devoid  of  smell. 

Persons  narcotized  with  carbonic  acid  may  be  restored  to  life  and 
health  by  prompt  removal  to  the  fresh  air,  or  by  artificial  respiration. 

Poisoning  with  carbonic  oxide  is  a  much  more  serious  matter, 
and  admitting  fresh  air,  or  even  pure  oxygen  gas,  is  often  power- 
less to  overcome  the  poison  of  carbonic  oxide. 

When  the  draft  in  a  furnace  or  heater  is  insufficient  the  combus- 
tion is  only  partly  complete,  full  oxidation  of  the  carbon  of  the  fuel 
does  not  take  place,  and  carbonic  oxide  is  formed. 

The  escape  of  this  gas  into  a  room  should  be  carefully  guarded 
against.  Especial  care  should  be  taken  that  there  are  no  open 
joints  or  cracks  in  the  furnace  or  heater. 

Organic  nitrogenous  substances  exhaled  with  air  from  the  lungs 
are  poisonous,  and  their  presence  may  be  noted  in  the  stagnant, 
vitiated  air  of  a  crowded  and  unventilated  room. 


26  THE   SCHOOL   HOUSE. 

The  disagreeable  odor  known  as  the  u  schoolhouse  smell"  is 
occasioned  by  these  substances  and  the  odors  given  off  by  the  skin, 
stomach,  decayed  teeth,  and  unclean  persons  and  clothing. 

Brown  Sequard  and  Arsonval  made  extended  researches  into  the 
nature  of  these  nitrogenous  poisons.  They  condensed  the  exhala- 
tions from  the  lungs  of  men  and  dogs  and  obtained  a  liquid  with 
an  alkaline  reaction.  From  twp  to  four  cubic  centimeters  of  this 
liquid,  injected  into  the  veins  of  animals,  caused  a  slowing  of  the 
respiration,  dilation  of  the  pupils  of  the  eyes,  great  muscular 
weakness  and  a  very  rapid  pulse.  When  from  10  to  12  cubic 
centimeters  were  used  death  speedily  followed,  even  when  the  fluid 
had  been  boiled. 

Brown  Sequard  arranged  eight  air-tight  cages,  connected  with 
glass  tubes  from  one  to  the  other,  and  by  means  of  an  aspirator  air 
was  made  to  pass  from  cage  to  cage  successively.  A  rabbit  was 
placed  in  each  cage.  The  one  in  the  first  cage  received  pure  air; 
the  second,  air  vitiated  by  the  first  animal;  the  third,  air  polluted 
successively  by  two  rabbits,  etc.  Special  provisions  were  made 
for  the  removal  of  excrement.  The  eighth  rabbit  died  in  two  days, 
the  seventh  in  three  days,  and  so  on  till  the  death  of  the  third  one, 
in  eight  days.  The  first  and  second  animals  remained  alive. 

Quantitative  analysis  of  the  air  in  the  several  cages  showed  the 
carbonic  acid  could  not  have  caused  the  death  of  the  rabbits.  With 
bits  of  pumice  stone  impregnated  with  sulphuric  acid  placed  in  the 
glass  tube  between  the  sixth  and  seventh  cages,  the  rabbits  in  the 
seventh  and  eighth  cages  remained  well.  The  sulphuric  acid 
neutralized  the  particular  poison. 

Claude  Bernard  made  a  series  of  experiments  which  tend  to  show 
that  the  system  may  gradually,  in  some  degree,  acquire  a  toleration 
of  the  poisonous  principles  in  rebreathed  air. 

A  sparrow  was  inclosed  in  a  glass  globe.  It  hopped  about  for 
an  hour  as  actively  as  usual,  and  then  gradually  showed  signs  of 
suffering  from  rebreathing  the  air  poisoned  by  its  own  breath.  At 
the  end  of  the  second  hour  another  sparrow  was  placed  in  the  glass 
globe.  It  was  asphyxiated  by  the  foul  air  and  soon  died.  At  the 
end  of  the  third  hour  the  first  sparrow  became  unconscious.  Taken 
out  into  the  open  air  it  soon  recovered ;  when  replaced  in  the  glass 
globe  it  died  at  once. 

When  expired,  air  leaving  the  lungs  contains  about  400  parts  of 
carbonic  acid  in  10,000  of  air,  together  with  other  impurities. 

To  dilute  and  remove  these  products  of  respiration  a  large 
quantity  of  pure  air  must  be  supplied. 


THE    SCHOOL   HOUSE.  27 

Different  writers  vary  as  to  the  amount  of  air  required  for  the 
good  ventilation  of  occupied  rooms. 

Parkes  fixes  the  amount  of  fresh  air  per  person  per  hour 

For  adult  males,  3,500  cubic  feet. 

For  adult  females,  3,000  cubic  feet. 

For  children,  2,000  cubic  feet. 

For  a  mixed  community,  3,000  cubic  feet. 

Pettinkoffer  recommends  2,100. 

Dr.  Billings,  from  850  for  children  6.25  years  old  to  2,000  for 
those  of  14.88. 

It  may  be  fairly  considered  that  an  ordinary  adult  man  expires 
.7  of  a  cubic  foot  of  carbonic  acid  per  hour,  and  a  person  about 
twelve  years  old  averages  .6  of  a  cubic  foot,  and  that  3,000  cubic 
feet  of  air  per  hour  per  person  is  required  for  good  ventilation. 

Prof.  Carpenter,  in  his  excellent  work  on  ventilation,  says,  "  If 
we  take  the  CO2  as  an  index  of  the  character  of  ventilation,  and 
consider  that  each  person  uses  one-third  of  a  cubic  foot  of  air  per 
minute,  and  that  the  respired  air  contains  400  parts  in  10,000  of 
CO  2,  while  the  entering  air  contains  but  4,  we  can  calculate  the 
amount  of  air  which  must  be  provided  to  maintain  any  standard  of 
purity  desired.  The  formula  for  this  operation  would  be  as 
follows  : 

"  If  a  =  the  parts  of  CO2  in  10,000  thrown  out  in  respiration,  or 
other  impurities  ;  if  b  =  the  cubic  feet  of  air  used  per  minute ;  if 
n  =  the  standard  of  purity  to  be  preserved,  expressed  as  the  num- 
ber of  units  of  CO2  permissible  in  10,000,  and  C  =  the  number  of 
cubic  feet  of  air  required,  we  shall  have 

p_         ab 
=  (^=4) 

u  For  conditions  considered  for  each  adult  person,  a  =400,  b  =  J, 
so  the  formula  becomes 

C  =       133 

(*  — 4) 
By  taking  n  as  8,  C  =  33,  and  n  as  10,  C  =  22." 

This  very  nearly  agrees  with  several  hundred  tests  made  by  the 
writer. 

An  approximate  rule  for  calculating  the  amount  of  air  required 
per  capita  per  hour  to  keep  the  CO2  down  to  six  parts  in  10,000  of 
air  in  schoolrooms  and  halls,  is  by  allowing  3,000  cubic  feet  for  this 
purpose. 


28  THE    SCHOOL   HOUSE. 

For  other  ratios,  divide  6,000  by  the  difference  between  normal, 
or  four  parts  in  10,000,  and  the  ratio  of  purity  required. 
Example  : 


6  —  4=2,     6,000 


9—4=5,     6,000 


2  =  3, 000  for  6  parts. 


7—4=3,     6,000  —  3  =  2,000  for  7  parts. 
8 — 4  =  4,     6,000  — 4  =  1,500  for  8  parts. 


5  =1,200  for  9  parts. 


3,000  —  60  =  50  per  minute  for  6  parts. 
2,000  —  60  =  33.33  per  minute  for  7  parts. 
1,500  —  60  =  25  per  minute  for  8  parts. 
1,200  —  60  =  20  per  minute  for  9  parts. 

The  standard  for  schoolrooms  adopted  by  the  Massachusetts 
Inspectors  of  Public  Buildings  is  a  minimum  of  thirty  cubic  feet  of 
fresh  air  per  pupil  per  minute. 

In  many  of  the  well-ventilated  school  buildings  in  Massachusetts 
from  40  to  50  cubic  feet  of  fresh  air  per  minute  is  furnished  for 
each  pupil. 

Fifty  cubic  feet  of  fresh  and  properly  warmed  air  per  minute 
per  person  is  an  ample  but  not  excessive  amount  for  good  ventila- 
tion in  a  schoolroom. 

HUMIDITY. 

The  amount  of  CO2  expelled  in  respiration  is  increased  greatly 
by  external  cold  and  diminished  by  heat ;  increased  by  moist  and 
decreased  by  dry  atmosphere. 

Humidity  or  moisture  in  air  has  much  to  do  with  comfort  and 
the  sensation  of  heat  or  cold. 

When  the  air  is  saturated  with  moisture  water  is  deposited  on 
bodies  which  readily  conduct  heat  and  are  of  a  lower  temperature 
than  the  surrounding  atmosphere. 

No  evaporation  from  the  body  will  take  place  when  the  air  is 
saturated  with  moisture. 

When  the  air  is  deprived  of  moisture  it  evaporates  water  from 
the  body,  causing  an  unpleasant  sensation. 

Heat  increases  the  power  of  air^  to  contain  moisture,  but  to 
remove  moisture  from  the  air  it  must  be  cooled. 

In  schoolhouses  where  an  ample  quantity  of  moderately  warmed 
air  is  supplied  there  is  seldom  complaint  of  dryness  of  the  air. 

It  has  been  found  that  much  better  results  have  been  obtained 
when  the  extra  amount  of  fuel  used  to  evaporate  a  considerable 
quantity  of  water  has  been  expended  in  warming  a  larger  quantity 
of  air. 


THE   SCHOOL    HOUSE.  29 

It  is  seldom  that  any  special  provision  is  made  to  moisten  the 
atmosphere  of  schoolrooms. 

Should  a  little  moisture  be  desired  in  schoolhouses  heated  by 
steam,  it  can  be  supplied  by  opening  an  air-valve  in  a  radiator  and 
allowing  steam  to  escape  into  the  air  passing  over  the  radiator.^ 

To  feel  comfortable  and  produce  the  best  results  in  ventilation, 
air  should  be  from  50  to  60  per  cent  saturated  with  moisture. 

LIGHTS. 

The  lights  used  in  a  room  are  one  source  of  vitiation  of  air.  An 
ordinary  gas  burner  contaminates  a  quantity  of  air  equivalent  to 
that  vitiated  by  from  four  to  five  persons,  and  allowance  should  be 
made  for  this  quantity  in  calculating  the  amount  of  fresh  air 
required. 

In  large  assembly  halls  lighted  by  gas  special  ventilation  should 
be  provided  above  the  clusters  of  gas  lights  to  quickly  remove  the 
vitiated  air  and  prevent  it  from  mingling  with  the  air  of  the  room. 
Where  electric  lights  are  used  it  is  only  required  to  allow  for  their 
heating  effect  in  large  or  crowded  places  of  assemblage. 

The  size  of  ordinary  schoolrooms  should  be  such  that  a  sufficient 
quantity  of  fresh  air  can  be  introduced  and  foul  air  removed 
without  causing  uncomfortable  drafts. 

It  is  the  number  of  occupants  and  not  the  size  of  the  room  that 
determines  the  amount  of  air  that  should  be  supplied. 

Rules  calling  for  the  change  of  air  in  a  room  a  given  number  of 
times  per  hour,  without  regard  to  the  number  of  occupants,  are 
erroneous,  and  should  not  be  adopted  in  designing  a  system  of 
ventilation. 

TESTING  THE  PURITY  OF  AIR. 

It  is  not  always  convenient  to  have  a  chemical  test  made  in  a 
laboratory  of  the  purity  of  air  from  a  schoolroom  or  assembly 
hall ;  but  an  approximate  test  can  be  made  in  the  schoolroom  by 
the  use  of  a  simple  apparatus  known  as  u  Professor  Wolpert's  Air 
Tester,"  and,  if  carefully  made,  will  indicate  near  enough  for  all 
practical  purposes  whether  the  air  is  contaminated  to  such  an 
extent  as  to  render  it  unfit  for  respiration. 

A  comparison  of  thirteen  tests  of  air  for  carbonic  acid  (CO2) 
made  with  a  Wolpert  air  tester  and  of  air  taken  at  the  same  time 
and  placed  in  glass  flasks  for  laboratory  analysis,  showed  an 
average  difference  of  only  sixty-seven  one  hundredths  of  one  part 
in  ten  thousand  parts  of  air — the  laboratory  analyses  showing  only 


30  THE    SCHOOL    HOUSE. 

this  quantity  of  carbonic  acid  (CO2)  in  excess  of  the  amount 
shown  by  the  Wolpert  tester. 

Care  must  be  taken  to  have  a  saturated  solution  of  clear  lime- 
water  and  also  in  using  the  apparatus. 

The  apparatus  consists  of  a  simple  rubber  bulb  (A)  of  a 
capacity  of  fifty-two  cubic  centimeters,  a  glass  outlet  tube  (B) 
with  a  constriction  near  its  extremity  (E).  The  glass  test-tube 
(C),  which  is  twelve  centimeters  in  length  and  twelve  'millimeters 
in  diameter,  has  a  horizontal  mark  (F)  near  the  bottom,  indicating 
the  point  to  which  it  must  be  filled  with  perfectly  clear  lime-water 
to  contain  three  cubic  centimeters.  The  bottom  of  the  tube  has 
a  black  mark  (D)  made  by  attaching  a  piece  of  black  glass.  A 
small  wooden  stand,  a  brush  or  swab,  a  vial  of  vinegar  for 
cleaning  the  tube,  and  a  bottle  of  perfectly  clear  and  saturated 
lime-water,  complete  the  outfit,  and  for  convenience  in  carrying 
may  all  be  inclosed  in  a  neat  case. 

Where  a  number  of  tests  are  to  be  made  time  may  be  saved  by 
having  several  test-tubes  and  bulb  outlet  tubes  in  the  case,  as  a 
clean  tube  should  be  used  for  each  test. 

DIRECTIONS  FOR  USING  PROFESSOR  WOLPERT'S  AIR  TESTER. 

By  S.  W.  ABBOTT,  M.D.,  Secretary  Massachusetts  State  Board  of  Health. 

In  order  to  use  the  instrument,  the  lime-water  (saturated  solution)  should 
be  poured  into  the  test-tube  till  it  reaches  the  horizontal  mark.  Press  down 
the  bulb  with  the  thumb,  so  as  to  expel  the  air  within  it  as  completely  as 

possible,  and  allow  it  to  fill 

PROF.  WOLPERT'S  AIR  TESTER   ^^^^\      with  the  air  of  the  a?art- 

E;  ,     ^^     I!      \       ment,  insert  the  small  tube 

D\  V— r  ^  ^JE         .        I       into  the  lime-water  nearly  to 

^^  ;'  ^S        the  bottom,  and  again  expel 
the  air   with  moderate   rap- 

FlG-  10-  idity,  so  that  the  bubbles  may 

rise  nearly  to  the  top  of  the  tube,  but  do  not  overflow,  taking  care  to  continue 
the  pressure  of  the  thumb  till  the  small  tube  is  removed  from  the  lime-water. 
Repeat  this  process  until  the  mark  upon  the  bottom  of  the  test-tube  is  ob- 
scured by  the  opacity  produced  by  the  reaction  of  the  carbonic  acid  upon 
the  lime-water,  the  observer  looking  downwards  through  the  lime-water, 
from  the  top  of  the  test-tube. 

With  very  foul  air  it  is. necessary  to  examine  the  mark  after  filling  and 
discharging  the  bulb  a  few  times  only;  with  good  air  it  must  be  filled 
twenty-five  times  and  upwards. 

After  each  observation  the  test-tube  must  be  washed  out  and  wiped  dry. 
If  a  white  incrustation  forms  upon  the  tube,  it  may  be  easily  removed  with 
a  little  vinegar,  after  which  the  tube  should  be  thoroughly  washed  with  pure 
water  and  dried. 


THE   SCHOOL   HOUSE. 


31 


If  the  mark  becomes  obscured  after  filling  the  bulb  ten  or  fifteen  times 
only,  the  air  of  an  apartment  is  unfit  for  continuous  respiration. 

The  instrument  should  be  used  by  daylight  over  a  white  ground,  as  a  sheet 
of  writing  paper,  and  care  should  be  taken  not  to  vitiate  the  result  by  the 
observer's  own  breath. 

The  following  approximate  table  is  taken  from  the  article  by  Professor 
Wolpert,  the  first  column  representing  the  number  of  fillings  of  the  bulb, 
and  the  second  column  the  parts  per  10,000  of  carbonic  acid  in  a  given 
sample  of  air. 

TABLE    1. 


Number 
of 
Fillings. 

Carbonic 
Acid 
per  10,000. 

Number 
of 
Fillings. 

Carbonic 
Acid 
per  10,000. 

Number 
of 
Fillings. 

Carbonic 
Acid 
per  10,000. 

1 

200. 

21 

9.5 

41 

4.9 

2 

100. 

22 

9.1 

42 

4.8 

3 

67. 

23 

8  7 

43 

4.6 

4 

50. 

24 

8.3 

44 

4.5 

5 

40. 

25 

8. 

45 

4.4 

6 

33. 

26 

7.7 

46 

43 

7 

29. 

27 

7.4 

47 

42 

8 

25. 

28 

7.1 

48 

4.1 

9 

22. 

29 

6.9 

49 

4.1 

10 

20. 

30 

6.6 

50 

4. 

11 

18. 

31 

6.4 

51 

3.9 

12 

16. 

32 

63 

52 

3.9 

13 

15. 

33 

6.1 

53 

38 

14 

14. 

34 

5.9 

54 

3.7 

15 

13. 

35 

5.7 

55 

3.7 

16 

12.5 

36 

5.5 

56 

3.6 

17 

12. 

37 

5.4 

57 

3.5 

18 

11. 

38 

5.3 

58 

3.5 

19 

105 

39 

5  1 

59 

34 

20 

10. 

40 

5. 

60 

3  3 

If  the  table  is  not  at  hand  for  ready  reference,  the  approximate 
amount  of  carbonic  acid  (CO2)  in  10,000  parts  of  any  sample  of 
air  may  be  obtained  by  dividing  200  by  the  number  of  fillings. 

Example  :     200  -f-  10  =  20  parts  of  CO2 
200-^25  =    8  parts  of  CO 2 

PREPARATION  OF  LIME-WATER  FOR  USE  WITH 
PROFESSOR  WOLPERT'S  AIR  TESTER. 

Lime-water  purchased  at  a  drug  store  is  ordinarily  worthless  for 
testing  the  purity  of  air,  and  should  never  be  used  for  that  purpose. 

Inspector  John  T.  White  and  the  writer  prepared  lime-water  for 
use  with  Professor  Wolpert's  air  tester  in  the  following  manner. 

The  best  unslaked  lime  made  from  marble  is  carefully  slaked  in 
distilled  water  in  a  clean  glass  bottle,  care  being  taken  to  put  in 


32 


THE    SCHOOL   HOUSE. 


but  a  small  quantity  at  a  time  to  prevent  breaking  the  bottle  by  the 
heat  generated  during  the  slaking. 

After  the  lime  has  settled  the  first  water  is  decanted  off  and  the 
slaked  lime  carefully  washed  with  distilled  water,  allowing  the  lime 
to  settle  before  pouring  off  the  wash  water.  The  bottle  is  then 
nearly  filled  with  distilled  water  and  shaken  at  intervals  for  several 

days,  the  bottle  being  carefully  closed 
during  the  time  with  a  tight-fitting  paraf- 
fined cork  or  ground-glass  stopper. 

A  considerable  quantity,  say  one-half 
inch  or  more,  of  the  undissolved  lime, 
should  always  remain  in  the  bottom  of  the 
bottle. 

After  the  lime  has  thoroughly  settled 
and  the  water  has  become  perfectly  clear, 
a  sufficient  quantity  may  be  transferred  to 
a  small  bottle  for  use  with  the  apparatus. 
The  following  described  apparatus  is 
used  to  prevent  the  lime-water  absorbing 
carbonic  acid  from  the  air  while  being 
poured  from  one  bottle  to  the  other. 

The  large  bottle  (A)  containing  the 
clear  lime-water  (L),  with  the  undissolved 
lime  (M),  in  the  bottom  is  fitted  with  a 
stopper  (C),  through  which  a  glass  tube 
(D)  is  passed  and  extended  well  below 
the  surface  of  the  lime-water,  but  not  too 
close  to  the  undissolved  lime  ;  and  the  glass 
tube  (D)  is  connected  with  another  glass 
tube  (I)  by  the  rubber  tubing  (E)  which 
has  inserted  into  it  a  larger  glass  tube  or  long  bulb  (F)  consist- 
ing of  two  parts  held  together  by  a  piece  of  rubber  tubing  (G). 
The  larger  tube  or  bulb  is  made  in  two  pieces  to  allow  cotton  fiber 
as  a  filter  (H)  to  be  easily  inserted  or  removed.  TJie  lower  glass 
tube  (I)  passes  into  the  small  bottle  (B),  the  mouth  of  which  is 
loosely  filled  with  cotton  (K) . 

The  larger  bottle  (A)  being  placed  on  a  table  or  shelf,  and  the 
small  bottle  (B)  on  the  floor  or  a  lower  shelf,  the  lower  end  of 
the  tube  (I)  is  placed  in  the  mouth  of  the  operator  and  the  air  is 
sucked  out  till  the  lime-water  flows  freely,  the  siphoning  being 
continued  till  sufficient  lime-water  has  passed  through  to  clear  the 


FIG.  11, 


THE    SCHOOL    HOUSE.  33 

tubes.  The  lower  tube  (I)  is  inserted  into  the  lower  bottle  and 
cotton  fibre  loosely  placed  in  its  mouth. 

The  clear  lime-water  will  then  be  siphoned  into  the  small  bottle 
without  coming  in  contact  with  the  outer  air. 

When  filled,  the  small  bottle  must  be  carefully  closed  with  a 
tight-fitting  ground  glass  stopper. 

MEASUREMENT  OF  AIR. 

An  anemometer  is  an  instrument  for  measuring  the  velocity  of 
air  currents.  It  consists  of  a  number  of  blades  set  at  an  angle  on 
a  shaft  and  inclosed  within  a  rim  or  circular  casing.  The  blades 
are  constructed  of  light-weight  metal,  and  the  shaft  is  provided 
with  bearings  to  reduce  the  friction  as  much  as  possible.  The 
movement  of  the  air  in  the  direction  of  the  axis  of  the  shaft  causes 
the  shaft  to  rotate,  setting  in  motion  a  train  of  gears,  by  means  of 
which  the  index  hands  indicate  the  number  of  revolutions  and  the 
velocity. 

The  number  of  index  hands  required  depends  upon  the  use  for 
which  the  instrument  is  intended. 

Many  of  those  in  common  use  have  but  two  index  hands,  one 
index  for  100  revolutions,  and  one  for  1000. 

Anemometers  intended  to  be  kept  running  in  one  place  for  a 
considerable  time  have  more  index  hands,  each  index  successively 
recording  ten  times  the  next  lower  index. 

The  four-inch  u  Byram's  "  with  two  indices  has  been  found  by 
the  writer  to  be  a  very  convenient  sized  and  reliable  instrument. 
Those  of  'larger  size  are  too  cumbersome,  and  cannot  be  used  to 
advantage  in  testing  the  velocity  in  different  parts  of  a  small  duct 
or  opening.  The  small  two-and-one-half  inch  size,  while  con- 
venient to  carry  in  the  pocket,  is  not  usually  quite  as  reliable  as 
the  four-inch  pattern. 

A  correction  table  is  usually  furnished  by  the  manufacturer  for 
each  instrument,  which  gives  the  correction  to  be  allowed  for 
different  speeds. 

For  convenience  it  is  well  to  have  a  special  adjustment  made, 
according  to  the  work  to  be  done,  by  some  reliable  party  having 
the  proper  means  for  rating  the  instrument. 

A  normal  rating  at  300  feet  per  minute  is  a  convenient  speed  for 
ordinary  schoolhouse  work. 

Where  the  instrument  is  used  frequently  it  is  advisable  to  have  it 
tested  at  intervals. 


34  THE    SCHOOL   HOUSE. 

If  a  number  of  instruments  are  used  by  several  persons  who  can 
meet  occasionally  at  a  given  place,  it  is  advisable  that  one  carefully 
tested  instrument  be  kept  as  a  standard  by  which  others  can  be 
tested  without  the  expense  and  delay  of  sending  them  away. 

A  convenient  way  of  testing  by  means  of  the  standard  instrument 
is  to  cover  with  a  board  an  opening  through  which  a  constant 
current  passes,  preferably  one  through  which  the  flow  is  caused  by 
a  fan.  In  the  board  cut  two  openings  side  by  side,  into  which  the 
two  anemometers  can  be  easily  placed,  but  fitting  reasonably  tight. 
By  changing  the  anemometers  from  one  opening  to  the  other  and 
noting  the  velocity  for  a  given  time,  fairly  good  comparisons  can  be 
had  as  to  the  running  of  the  instruments. 

The  speed  of  the  fan  wheel  can  be  adjusted  by  changing  the 
angle  of  inclination  of  the  blades.  When  the  fan  wheel  is  running 
too  slow  a  greater  speed  will  be  recorded  by  reducing  the  angle  or 
flattening  the  blades.  If  running  too  fast  the  angle  should  be 
increased. 

In  changing  the  angle  of  the  blades  care  should  be  taken  to  have 
the  pitch  of  each  blade  the  same. 


FIG.  12. 

After  the  instrument  has  been  tested  and  rated,  and  before  using 
it,  a  template  can  be  made  of  stout  sheet  metal  or  wood  which  will 
fit  the  pitch  of  the  blades. 

The  accompanying  diagram  shows  the  form  of  the  template. 

By  placing  the  edge  A-A  on  the  top  of  the  casing,  with  the 
perpendicular  edge  B  resting  on  the  inner  side  of  the  casing,  the 
inclined  side  C  will  give  the  pitch  or  inclination  of  the  blades. 

An  accurate  instrument  is  required  to  obtain  correct  measure- 
ments of  the  velocity. 


THE    SCHOOL   HOUSE. 


35 


In  measuring  the  velocity  of  air  at  inlets  and  outlets,  especially 
in  school-rooms,  care  must  be  exercised  to  obtain  a  correct  average 
velocity;  also  the  net  available  or  working  area  of  the  opening.  . 

At  an  inlet  or  outlet  from  a  room  the  velocity  of  the  air  currents 
varies  materially  in  different  parts  of  the  opening.  This  variation 
is  owing  to  a  variety  of  causes,  of  which  the  form  and  direction  of 
the  duct  or  shaft  is  one  of  the  principal.  The  ordinary  inlet  for 


FIG.  13. 


supplying  air  to  a  schoolroom  should  have  a  curve  at  the  top,  and 
the  bottom  of  the  inlet  should  have  the  wall  on  the  front  of  the  duct 
cut  away,  curved,  or  beveled  down.  The  tendency  of  the  air  flow- 
ing up  the  warm -air  flue  is  to  strike  against  the  top  of  the  flue  and 
be  deflected  into  the  room.  Where  the  top  is  properly  curved,  the 
direction  of  the  warm  air  current  is  changed  in  a  more  satisfactory 
manner  than  when  the  top  is  flat.  If  the  bottom  of  the  opening  is 
flat  and  horizontal,  the  current  is  carried  up  too  high  before  it 
changes  its  direction.  This  is  particularly  noticeable  in  flues- 
having  walls  eight  inches  thick  with  the  added  thickness  of 
studding  and  plastering. 

The  available  or  working  area  of  the  opening  is  often  greatly 
reduced  from  this  cause,  and  in  some  cases  one-third  or  more  of 
the  area  is  not  available  and  the  volume  of  air  which  should  pass 
through  the  whole  opening  is  forced  into  a  space  one-third  or  more 
smaller  than  it  should  be,  thereby  increasing  the  velocity  to  an 
undesirable  point. 

Upon  holding  an  anemometer  on  the  lowest  part  of  the  inlet 
opening,  the  fan  wheel  will  sometimes  indicate  an  inward  or 
reversed  current,  caused  by  an  eddy  above  the  flat  top  of  the  front 
wall  of  the  duct. 


36  THE    SCHOOL   HOUSE. 

In  other  cases  the  current  will  be  stronger  at  one  end  of  the  inlet 
opening  than  at  the  other. 

Again  it  will  be  diagonally  up  and  across  the  opening,  or  it  may 
be  in  the  form  of  an  arch,  or  strong  at  one  end  and  weak  at  another 
point  in  a  perpendicular  line. 

Occasionally  the  lowest  velocity  will  be  in  the  center  of  the 
opening.  '  These  different  currents  are  produced  by  offsets  or 
changes  in  the  form  and  direction  of  the  duct  before  it  reaches  the 
opening. 

In  measuring  the  inflowing  air  the  various  currents  and  velocities 
must  be  carefully  noted  in  order  to  obtain  a  correct  average. 

In  the  greater  number  of  cases  the  velocity  will  be  highest  at  the 
top  of  the  inlet  opening,  decreasing  down  to  a  point  towards  the 


FJG.  15.  FIG.  16.  FIG.  17. 

bottom,  where  no  movement  of  the  anemometer  wheel  will  take 
place. 

In  measuring  the  amount  of  air  coming  through  the  inlet  it  is 
advisable  to  place  the  anemometer  in  front  of  the  bottom  of  the 
inlet  and  gradually  raise  it  till  the  top  of  the  blades  will  strike  the 
incoming  current,  then  note  this  point  and  cover  the  opening  below 
it  with  a  piece  of  rubber  cloth  having  small  hooks  on  the  upper 
edge  to  fasten  to  the  register  or  grill  over  the  opening.  This  will 
cause  any  incoming  air  below  this  point  to  be  sent  through  the 
upper  and  uncovered  part  of  the  opening. 

Then  measure  the  length  and  height  of  the  uncovered  part  of  the 
opening  for  the  effective  or  working  area. 

If  a  register  face  of  any  of  the  common  cast-iron  patterns  is  used 
to  cover  the  opening  a  deduction  of  one-third  should  be  made  from 
the  working  area  as  found  by  the  above  measurement.  With  some 
cast-iron  register  faces  a  larger  deduction  will  be  required. 

With  the  ordinary  wire  grill  pattern  over  the  opening  about 
one-tenth  will  be  a  fair  deduction.  With  some  patterns  it  may  be 
one-eighth. 


THE    SCHOOL   HOUSE.  37. 

Care  should  be  taken  to  hold  the  anemometer  with  the  edge  of 
the  casing  parallel  with  the  register  face  or  grill.  Air  striking  the 
blades  at  different  angles  will  give  different  readings  on  the  index. 

It  is  usual  to  take  three,  five  or  nine  measurements  with  the 
anemometer  placed  as  shown  in  diagrams,  Figures  15,  16  and  17. 

If  the  opening  is  circular  the  anemometer  may  be  placed  as 
shown  in  Fig.  18. 

If  a  very  careful  measurement  of  the  air  is  required  it  may  be 
advisable   to    construct   a    frame    the    size    of    the    opening    to  be 
measured   and  one  foot  deep,  and  divide  the  area 
into  squares  with  sides  of  six  inches  by  stretching 
pieces  of  cord  across  the  outer  edge  of  the  frame, 
then  holding  the  anemometer  for  a  given  time  —  say 
one  minute   each  —  with   the  center    of   the  wheel 
opposite  the  intersections  of  the  cords. 

The  total  of  the  different  readings  of    the  index 
divided  by  their  number  will  give  a  fair  average  of  the  velocity  of 
the  current. 

The  average  velocity,  multiplied  by  the  net  available  square  feet 
of  opening,  will  give  the  number  of  cubic  feet  of  air  passing  in  a 
given  time.  If  the  time  of  each  reading  of  the  index  is  one  minute 
the  amount  will  be  in  cubic  feet  per  minute.  This,  divided  by  the 
number  of  seats  in  the  room,  will  give  the  number  of  cubic  feet  of 
air  supplied  per  minute  for  each  seat. 

If  the  amount  per  hour  is  required,  multiply  the  supply  per 
minute  by  sixty. 

The  practice  of  moving  the  anemometer  over  different  parts  of 
the  opening  while  taking  a  measurement  is  not  a  good  one,  espe- 
cially if  the  lower  part  of  the  opening  is  not  an  available  or 
working  area. 

If  the  instrument  is  held  at  the  top  of  the  opening  till  the  fan 
wheel  has  acquired  the  greatest  velocity  obtainable  in  that  position, 
and  is  then  quickly  moved  to  the  bottom  of  the  opening,  the 
readings  will  be  incorrect.  The  momentum  of  the  wheel  will 
continue  it  in  motion  till  after  it  is  gone  ,below  the  available  work- 
ing area,  and  if  the  instrument  is  raised  again  to  the  top  of  the 
opening  the  speed  will  be  again  raised  to  the  high  point. 

The  writer  recalls  an  instance  in  which  a  person  who  claimed  to 
be  an  expert  heating  and  ventilating  engineer  had  installed  a 
heating  and  ventilating  apparatus  in  a  new  schoolhouse. 

He  had  succeeded  in  securing  from  the  building  committee  a 
contract  for  the  work  without  giving  any  guarantee  that  the  work 


38  THE   SCHOOL    HOUSE. 

should  be  up  to  the  state  requirements,  or  that  it  should  be  tested 
by  the  state  inspector. 

Being  desirous  of  obtaining  his  pay,  and  being  a  good  talker,  he 
had  induced  the  building  committee  to  be  present  at  the  building 
on  a  day  when  the  conditions  of  temperature  and  wind  were 
favorable  for  obtaining  good  results. 

His  talk  to  the  committee  was  like  this  :  "  Now,  gentlemen,  I 
have  given  you  a  first-class  piece  of  work,  and  in  order  that  you 
may  see  what  excellent  results  we  have  obtained  I  have  asked  you 
to  be  present  today  and  see  the  apparatus  tested. 

u  To  satisfy  you  that  the  test  is  fairly  made  I  will  ask  one  of  you 
gentlemen,  to  give  me  th*e  time  by  your  watch,  one  minute,  while 
I  use  this  anemometer  to  ascertain  at  what  velocity  the  air  enters 
the  room."  Showing  the  anemometer  to  the  committee,  he 
explained  its  use  and  how  to  read  the  indices,  and  had  them  note 
the  position  of  the  hands  of  each  index. 

Holding  the  instrument  near  the  top  of  the  opening,  he  started 
and  stopped  it  at  a  signal  from  the  man  holding  the  watch. 
Observing  the  index,  the  committee  noted  the  velocity  recorded  to 
be  550  feet  per  minute.  Then  measuring  the  full  area  of  the 
opening,  which  was  covered  by  an  ordinary  register  face,  he  used 
his  pencil  .and  paper,  showing  the  committee  the  figures,  of  which 
they  took  a  copy.  u  Now,  gentlemen,  the  opening  is  30  by  20 
inches,  which  made  an  area  of  600  square  inches,  or  4.16  square 
feet.  The  velocity  is  550  feet  per  minute,  which  gives  you  2,288 
cubic  feet  of  fresh  air  per  minute  for  the  48  pupils,  or  47^  cubic 
feet  per  minute  for  each  scholar.  You  will  see  this  is  very  much 
better  than  I  told  you  I  would  do." 

The  committee  were  satisfied,  and  paid  the  bill.  After  a  time 
complaints  were  made  of  defects  in  the  system,  and  the  state 
inspector  was  asked  what  could  be  done  to  remedy  them,  as  the 
contractor  would  not  do  it. 

When  a  test  was  made  by  the  inspector  the  committee  were 
greatly  surprised  to  see  the  report  of  the  air  actually  supplied. 
Other  defects  were  pointed  out  in  the  apparatus,  and  several 
hundred  dollars  were  expended  before  the  apparatus  was  made  to 
do  fair  work. 

The  volume  of  air  and  its  weight  per  cubic  foot  change  with  the 
temperature. 

In  measuring  and  computing  the  volume  of  air  its  temperature 
at  the  time  of  measurement  should  be  taken  into  account. 


THE   SCHOOL   HOUSE.  39 

In  comparing  one  measurement  with  another  the  volumes  should 
all  be  reduced  to  corresponding  volumes  at  zero.  (Absolute 
T  =  460°  below  zero.) 

Reduce  both  the  original  and  final  temperature  to  absolute 
temperatures.  Multiply  the  original  volume  by  the  final  absolute 
temperature  and  divide  by  the  original  absolute  temperature.  The 
quotient  will  be  the  final  volume. 

If  V=the  original  volume,  V\  =  final  volume,  Tx  =  original 
absolute  temperature,  and  T2=  final  absolute  temperature  ;  then 

V      .- 

I 

Example  :  What  will  be  the  volume  of  1800  cubic  feet  of  air  at 
a  temperature  of  100  degrees  F.  when  it  is  cooled  to  70  degrees  F.  ? 

,      1800  (460  +  70) 

i L  =  1703.57  cubic  feet. 

460  +  100 


WIND — VELOCITY  AND  PRESSURE. 

The  pressure  of  the  wind  varies  as  the  square  of  the  velocity, 
or  P~V2. 

The  square  of  the  velocity  in  miles  per  hour  multiplied  by 
.005  =P. 

The  square  root  of  200  times  the  pressure  equals  the  velocity,  or 
-^200  X  P  =  V. 

To  find  the  rate  at  which  air  is  moving,  divide  the  velocity  in 
feet  per  minute  by  .88  ;  the  answer  will  be  in  miles  per  hour. 

Example  :  300  feet  per  minute  =  300  -r-  .88  =  3.409  miles  per 
hour. 

To  find  the  pressure  in  pounds  per  square  foot,  multiply  the 
square  of  the  velocity  in  feet  per  second  by  .0023  ;  the  result  will 
be  pounds  pressure. 

Example :  300  feet  per  minute  =  5  feet  per  second,  and 
5  X  5  X  .0023  =  .0575  pounds. 

The  shape  of  the  surface  obstructing  the  wind  greatly  modifies 
the  pressure. 

The  pressure  upon  a  globe,  or  a  hemisphere  with  the  convex 
side  towards  the  wind,  is  only  about  one-half  the  pressure  on  a  flat 
surface  of  equal  diameter. 


40 


THE    SCHOOL   HOUSE. 


TABLE    2 

SHOWING   THE   NUMBER  OF  MILES  PER  HOUR  AND   PRESSURE  IN  POUNDS  PER 

SOJJARE  FOOT  ON  FLAT  SURFACES  AT  RIGHT  ANGLES  TO  THE 

CURRENT,  AT  VELOCITIES  PER  MINUTE. 


Feet 
per 
Minute. 

Miles 
Hour. 

Pressure 
in  Pounds 
per 
Sq.  Foot. 

Character  of  Wind. 

Feet 
per 
Minute. 

Miles 
Hour. 

Pressure 
in  Pounds 
per 
Sq.  Foot. 

Character  of  Wind. 

10 

.113 

.0000 

550 

6.249 

.1930 

20 

.227 

.0002 

600 

6.818 

.2300 

25 

.284 

.0004 

650 

7.386 

.2968 

30 

.340 

.0006 

700 

7.954 

.3125 

35 

.397 

.0008 

750 

8.522 

.3593 

40 

.454 

.0010 

800 

9.090 

.4087 

45 

.511 

.0013 

860 

9.658 

.4616 

50 

.568 

.0016 

900 

10.227 

.5175 

Gentle  breeze 

55 

.625 

.0019 

950 

10.795 

.5763 

Gentle  breeze 

60 

.681 

.0023 

1000 

11.363 

.6384 

Fresh  breeze 

65 

.738 

.0027 

1500 

17.405 

1.4375 

Light  wind 

70 

.795 

.0031 

2000 

22.727 

2.5553 

Brisk  wind 

75 

.852 

.0036 

2500 

28.407 

3.9918 

Strong  wind 

80 

.909 

.0041 

3000 

34.090 

5.7500 

Strong  wind 

85 

.966 

.0046 

3500 

39.772 

7.8255 

High  wind 

90 

1.022 

.0051 

Hardly  perceptible 

4000 

45.454 

10.2202 

Gale 

95 

1.079 

.0057 

4500 

51.131 

12.9375 

Gale 

100 

1.136 

.0063 

5000 

56.818 

15.9709 

Gale 

125 

1  420 

.0100 

5500 

62.499 

19.2982 

Strong  gale 

150 

1.704 

.0143 

6000 

68.181 

22.9954 

Violent  gale 

175 

1.988 

.0195 

Perceptible  breeze 

6500 

73.861 

26.9764 

Violent  gale 

200 

2.272 

.0255 

Pleasant  breeze 

7000 

79.545 

31.3020 

Hurricane 

250 

2.840 

.0398 

7500 

85.225 

35.9375 

Hurricane 

300 

3.409 

.0575 

\             i 

8000 

90.909 

40.8868 

Hurricane 

350 

3.977 

.0781 

8500 

96.589 

46.1554 

Hurricane 

400 

4  545 

.1021 

9000 

102.272 

51.7500 

Tornado 

450 

5.113 

.1294 

9500 

107.952 

57.7447 

Tornado 

500 

5  681 

.1596 

10000 

113.636 

63.8837 

Tornado 

CHAPTER    III. 


SOME  IDEAS  OF  VENTILATION. 

THE    law  requiring  the  ventilation  of   public  and   school 
buildings  in  Massachusetts  was  passed  in  1888. 
The  standard  was  fixed  by  the  inspection  department 
at  a  minimum  of  thirty  cubic  feet  of  fresh  air  per  minute  per  person  : 

Not  because  that  was  all  that  is  required  for  good  ventilation ; 
but  because  it  would  greatly  improve  existing  conditions  and  would 
be  about  as  much  as  could  then  be  reasonably  obtained  without 
incurring  considerable  additional  expense  in  a  large  number  of 
school  buildings. 

Many  persons  claimed  this  amount  was  excessive  and  could  not 
be  supplied  to  the  pupils  in  a  schoolroom  without  creating  almost 
a  gale  in  the  room. 

Some  of  the  heating  and  ventilating  contractors  refused  to  guar- 
antee any  such  amount,  claiming  that  such  a  quantity  of  air  could 
not  be  properly  heated. 

At  the  present  time  there  is  no  difficulty  in  furnishing  that  amount, 
and  perhaps  the  larger  part  of  the  work  designed  for  modern  school- 
houses  in  Massachusetts  now  gives  from  forty  to  fifty  cubic  feet  of 
fresh  air  per  minute  for  each  person  accommodated  in  a  school- 
room. A  guarantee  is  required  by  the  Massachusetts  inspectors 
that  certain  results  will  be  obtained  before  their  approval  of  plans 
and  specifications  for  heating  and  ventilating  is  given. 

THE  REQUIREMENTS  OF  "FORM  NO.  83,"  INSPECTION  DE- 
PARTMENT MASSACHUSETTS  DISTRICT  POLICE,  ARE  AS 
FOLLOWS  : 

In  the  ventilation  of  school  buildings  the  many  hundred  examinations 
made  by  the  inspectors  of  this  department  have  shown  that  the  following 
requirements  can  be  easily  complied  with  : 

1.  That  the  apparatus  will  with  proper  management,  heat  all  the  rooms, 
including  the  corridors,  to  70°  F.  in  any  weather. 

2.  That,  with   the  rooms  at  70°  and  a  difference  of   not   less   than  40° 
between  the  temperature  of  the  outside  air  and  that  of  the  air  entering  the 
room  at  the  warm-air  inlet,  the  apparatus  will  supply  at  least  thirty  cubic  feet 
of  air  per  minute  for  each  scholar  accommodated  in  the  rooms. 

3.  That  such  supply  of  air  will  so  circulate  in  the  rooms  that  no  uncom- 
fortable draught  will  be  felt,  and  that  the  difference  in  temperature  between 


42  THE    SCHOOL   HOUSE. 

any  two  points  on  the  breathing  plane  in  the  occupied  portion  of  a  room  will 
riot  exceed  3°. 

4.  That  vitiated  air  in  amount  equal  to  the  supply  from  the  inlets  will  be 
removed  through  the  ventiducts. 

5.  That  the  sanitary  appliances  will  be  so  ventilated  that  no  odors  there- 
from will  be  perceived  in  any  portion  of  the  building. 

To  secure  the  approval  of  this  department  of  plans  showing  methods  or 
systems  of  heating  and  ventilation,  the  above  requirements  must  be  guaran- 
teed in  the  specifications  accompanying  the  plans. 

With  a  mechanical  system  of  ventilation  the  allowance  of  40 
degrees  in  temperature  (Section  2)  should  be  omitted  in  the 
specifications,  as  it  was  intended  to  apply  to  gravity  systems. 

Many  persons,  some  of  them  members  of  school  committees, 
while  they  readily  admit  in  a  general  way  that  pure  air  is  essential 
to  health,  do  not  seem  to  be  aware  of  the  danger  of  impure  air  as  it 
exists  in  an  ordinary  schoolroom.  They  seem  to  think  that  as  some 
schoolhouses  never  have  been  ventilated  there  is  no  occasion  for  any 
anxiety  about  them  now. 

Many  old  school  teachers  say  they  never  had  any  difficulty  in  ven- 
tilating their  schoolrooms  by  means  of  the  windows.  Windows  are 
made  to  admit  light  and  not  air,  and  except  when  the  temperature 
of  the  outer  and  inner  air  is  so  nearly  equal  that  the  air  can  be  per- 
mitted to  circulate  freely  through  the  rooms  they  should  never  be 
depended  upon  for  ventilation. 

Besides,  it  costs  no  more  to  admit  the  same  amount  of  air  in  the 
proper  way,  and  warm  it  before  it  enters  the  room,  than  to  let  it  in 
cold  at  a  window  and  heat  it  after  it  is  in. 

The  saving  which  some  people  think  is  made  by  admitting  cold 
air  through  the  windows,  or  by  means  of  patented  devices,  is 
effected  only  so  far  as  the  amount  of  fresh  air  is  restricted. 

The  writer  remembers  a  hearing  given  by  the  legislative  com- 
mittee having  the  proposed  ventilation  law  under  consideration. 

A  man  of  good  standing  in  his  town,  who  had  held  various  official 
positions,  among  them  that  of  school  committeeman,  appeared  in 
opposition  to  the  bill  before  the  legislative  committee  at  one  of  the 
hearings.  He  said,  "Gentlemen,  this  talk  about  carbonic  acid  is 
all  humbug.  We  know  that  carbonic  acid  is  heavier  than  air.  You 
may  remember  what  we  were  taught  at  school  about  putting  pieces 
of  candle  on  an  inclined  board  and  pouring  carbonic  acid  out  of 
a  jar  —  that  it  would  flow  down  the  board  and  put  out  the  flame  of 
the  candles.  You  know  that  a  candle  will  not  burn  in  a  deep  hole 
or  well  where  carbonic  acid  has  settled  to  the  bottom.  Now  all  you 


THE    SCHOOL    HOUSE.  43 

have  got  to  do  to  get  rid  of  this  carbonic  acid  in  a  schoolroom  is  to 
cut  a  hole  in  the  floor  and  let  it  run  down  into  the  cellar,  and  if  you 
don't  want  it  in  the  cellar  just  cut  some  holes  in  the  outside  walls  at 
the  floor  and  let  it  run  outdoors." 

It  was  quite  evident  that  this  man  was  not  familiar  with  the 
law  of  diffusion  of  gases,  or  with  the  condition  of  the  warm  exhala- 
tions from  the  lungs. 

Another  man,  talking  with  a  friend,  stated,  u  This  matter  of  ven- 
tilation is  all  humbug.  When  I  went  to  school  there  was  no  ventila- 
tion in  the  schoolhouse.  Anyone  can  see  I  am  strong  and  hearty, 
although  I  am  well  along  in  years."  He  was  asked,  u  How  many 
were  there  in  your  school  when  you  went  ?  "  He  replied,  u  About 
forty."  How  many  of  them  are  living  now  ?  "  was  the  next  ques- 
tion. After  considerable  thought  he  replied,  "  Only  two,  as  far  as 
I  know."  The  friend  said,  u  Well,  the  balance  appears  to  be  on 
the  wrong  side  of  the  account,  if  your  theory  is  correct." 

In  a  small  country  school  the  inspector  had  induced  the  school 
committee  to  install  a  jacketed  stove,  build  a  vent  shaft  and  put  in 
a  small  heater  to  cause  an  outflow  of  foul  air  through  the  vent  shaft. 
This  gave  fair  ventilation  for  the  number  of  scholars  attending. 
Some  three  years  later  the  inspector  again  visited  this  school- 
house.  The  jacketed  stove  had  been  removed  and  an  old-fashioned 
wood-burning  stove  had  been  substituted.  The  foul  air  outlet  at 
the  floor  level  had  been  carefully  boarded  up.  On  opening  the 
iron  feed  door  and  looking  into  the  vent  shaft  it  was  found  that 
birds  had  used  the  top  of  the  heater  as  a  place  on  which  to  build 
nests.  There  were  two  nests,  one  upon  the  other,  indicating  that 
the  heater  had  not  been  used  for  two  years.  When  the  school 
committee  were  called  upon  to  explain  their  reason  for  making  the 
change  the  reply  was,  u  It  was  no  use  to  put  any  ventilation  in  that 
building.  When  the  air  got  bad  the  doors  and  windows  could  be 
opened.  It  cost  more  for  fuel  than  when  the  wood-burning  stove 
was  in  use." 

I  am  glad  to  say  that  committee  do  not  now  have  charge  of  the 
schools,  and  the  town  now  has  three  modern  and  well-ventilated 
schoolhouses. 

In  another  town  a  jacketed  stove  had  been  installed  in  a  one- 
room  schoolhouse.  After  a  year  had  passed  complaint  was  made 
that  the  system  of  ventilation  was  a  complete  failure,  and  that  the 
schoolroom  could  not  be  heated  and  the  air  was  bad.  When  the 
inspector  visited  the  building  he  found  that  a  board  had  been  care- 


44  THE    SCHOOL    HOUSE. 

4 

fully  fitted  over  the  fresh-air  inlet  to  the  jacketed  stove  and  a  round 
hole  two  inches  in  diameter  had  been  cut  in  the  board.  The  cause 
of  the  failure  to  heat  and  ventilate  this  room  was  apparent. 

In  one  city  in  which  modern  heating  and  ventilating  had  been 
provided  in  several  schoolhouses,  the  inspector  found  that  no  heat 
was  used  in  the  vent  shafts  in  any  of  the  buildings.  When  the 
janitors  were  asked  why  they  did  not  use  the  vent  shaft  heaters  in 
mild  weather,  they  gave  as  a  reason  that  the  superintendent  of 
schools  had  given  them  positive  orders  not  to  use  the  vent  shaft 
heaters,  as  he  considered  it  a  useless  and  extravagant  waste  of  fuel. 

Education  is,  however,  reducing  the  number  of  those  who  oppose 
providing  good  ventilation  in  schools,  churches  and  places  of 
assemblage.  The  necessity  of  a  large  amount  of  fresh  air  and  the 
practicability  of  obtaining  it  are  fast  coming  to  be  universally 
admitted. 

Nor  is  the  fear  at  first  entertained  of  an  enormously  increased 
expense  likely  to  be  realized. 

Good  ventilation  undoubtedly  costs  money,  but  the  expense  of 
the  new  methods  as  compared  with  the  old  is  more  with  the  first 
cost  of  the  appliances  than  with  the  cost  of  supplying  and  remov- 
ing the  air  after  such  appliances  have  been  put  in. 

CIRCULATION  OF  AIR. 

In  designing  a  system  of  heating  and  ventilation  one  of  the  most 
important  points  to  consider  is  the  proper  circulation  of  the  air 
used  for  conveying  the  heat  and  also  for  removing  the  impurities 
thrown  off  by  the  occupants  of  the  rooms,  or  from  any  other  source 
of  contamination. 

For  many  years  it  would  seem  that  very  little  attention  was  given 
to  this  matter.  The  only  thought  apparently  was  where  the  inlets 
and  outlets  could  be  most  conveniently  placed,  without  regard  to 
their  efficiency. 

On  the  proper  location  of  the  inlets  and  outlets  will  depend 
the  efficiency  and  economy  of  the  heating  and  ventilation.  A  large 
amount  of  heat  and  air  may  be  brought  into  a  room,  but  if  it  is 
allowed  to  escape  without  proper  circulation  very  little  benefit  will 
be  derived. 

We  have  seen  schoolrooms  where  the  warm  air  was  brought  in 
through  a  register  in  the  floor  and  was  allowed  to  escape  through 
a  register  in  the  ceiling  or  side  wall  near  the  ceiling  and  almost 
over  the  inlet. 


THE    SCHOOL    HOUSE.  45 

In  other  cases  the  inlets  and  outlets  were  placed  in  the  outer  and 
most  exposed  corners  of  the  room,  where  the  fresh  air  that  leaked 
in  around  the  windows  was  taken  out  through  the  vent  ducts, 
having  done  nothing  but  cooled  the  air  in  the  immediate  vicinity  of 
the  vent  duct. 

Again,  the  warm  fresh  air  has  been  brought  in  through  an  inlet 
properly  located,  but  the  outlet  being  placed  directly  opposite  the 
inlet,  the  air  would  pass  across  the  room  and  go  out  at  the  outlet, 
doing  but  very  little  good;  in  fact,  only  causing  uncomfortable 
drafts  on  whoever  had  the  misfortune  to  be  located  between  the 
inlet  and  the  outlet. 

In  many  instances  the  warm  air  would  be  taken  in  at  the  inner 
or  warm  angle  of  the  room  while  the  outlet  was  placed  near  an 
outside  or  exposed  wall. 

Sometimes  it  would  appear  that  the  designer  of  the  system  had 
devised  some  scheme  that  would  do  the  work  in  the  most  unsatis- 
factory manner. 

In  one  u  system  "  that  was  installed  in  many  school  buildings 
(but  which  is  not  at  this  time  allowed  in  Massachusetts),  the  outlets 
were  long  narrow  openings  placed  at  the  floor  level  in  the  outside 
walls  and  often  under  the  windows.  The  air  was  taken  across 
under  the  floors  between  the  floor  timbers  and  down  into  what  was 
called  a  u  f oul  air  gathering  room,"  and  then  passed  over  screens 
placed  below  the  seats  in  the  sanitary  closets  (perhaps  the  term 
unsanitary  closets  would  be  more  appropriate).  Here  it  was 
supposed  to  dry  the  excrement,  which  was  afterwards  to  be  burned 
by  pouring  a  quantity  of  oil  over  it  and  then  setting  the  oil  and 
accumulated  paper  on  fire. 

In  such  a  u  system"  the  air  which  came  into  the  room  around 
the  windows,  or  was  cooled  on  the  glass  surface,  would  drop  down 
to  the  floor,  and,  if  there  was  a  strong  fire  in  the  large  heater  in  the 
ventilating  shaft,  after  having  been  passed  through  the  space  under 
the  "  cremating  closets"  would  be  taken  out  of  the  building,  while 
the  vitiated  air,  especially  in  the  inner  or  warm  parts  of  the  room 
occupied  by  the  pupils,  would  remain. 

By  chemical  tests  the  writer  has  many  times  found  the  air  to  be 
purer  in  the  so-called  "  foul  air  gathering  room  "  than  about  the 
seats  where  the  pupils  were  located. 

Another  serious  defect  in  this  "  system"  was  the  danger  of  odors 
and  gases  being  forced  back  into  the  schoolroom  when  there  was 
no  fire  in  the  vent  shaft  heater,  or  where  the  vent  shafts  came 
through  the  roof  in  a  location  to  be  affected  by  adverse  air  currents 
or  wind. 


46  THE    SCHOOL    HOUSE. 

In  addition  to  these  defects  was  the  danger  from  fire.  The  rough 
floor  timbers  and  boards  soon  became  covered  with  fine  particles 
of  lint  and  other  material  which  was  drawn  in  by  the  air  current. 
If  fire  from  any  cause  should  get  into  these  under-floor  ducts  it 
would  spread  with  great  rapidity  through  the  entire  building. 

The  Massachusetts  law  which  prohibits  wooden  ducts  for  heating 
and  ventilating  public  buildings  soon  put  a  stop  to  the  further 
extension  of  this  dangerous  u  system." 

Another  u  system  "  was  introduced  into  some  school  buildings, 
by  means  of  which  it  was  proposed  to  draw  the  air  down  from  the 
upper  stories  through  a  duct  which  entered  the  bottom  of  the  vent 
shaft,  and  which  was  enlarged  at  each  story  as  it  came  down  to 
the  basement,  where  air  was  to  enter  the  vent  shaft  and,  after 
being  warmed  by  a  u  stack  heater,"  or  small  furnace,  was  to 
escape  through  the  central  vent  shaft. 

The  opening  from  the  upper  story  room  was  supposed  to  be 
sufficient  to  furnish  the  required  ventilation  for  the  room  in  which 
it  was  placed.  The  duct  was  enlarged  at  the  next  floor  below  to 
twice  its  original  size,  and  so  on. 

The  designer  of  this  u  system"  did  not  take  into  consideration 
the  fact  that  moving  air  will  follow  the  line  of  least  resistance. 
It  was  often  found  that,  while  an  anemometer  would  show  a 
velocity  of  500  feet  or  more  per  minute  at  the  lower  opening,  the 
movement  of  air  at  the'  upper  opening  was  not  strong  enough  to 
cause  any  movement  of  the  anemometer  wheel. 

Several  other  u  systems  "  were  brought  forward  and  introduced 
by  various  experimenters,  who  in  many  cases  tested  their  theories 
at  the  expense  of  various  cities  and  towns. 

In  1888  and  1889  the  writer,  in  company  with  State  Inspector 
the  late  John  T.  White,  made  a  large  number  of  tests  of  the 
circulation  of  air  in  different  schoolhouses  in  Massachusetts,  by 
means  of  smoke  and  otherwise,  to  ascertain  what  should  be  the 
proper  location  of  the  inlets  and  outlets  to  secure  a  good  circula- 
tion of  the  air  and  heat;  also,  to  determine  the  proper  size  and 
form  of  inlets  and  outlets  for  the  ventilation  of  schoolrooms. 

It  was  found  from  these  tests  that  the  best  results  would  be 
obtained  by  varying  the  location  of  the  inlets  and  outlets  to  meet 
the  different  locations  of  the  cold  or  exposed  walls. 

In  a  schoolroom  having  two  cold  and  exposed  walls  the  inlet 
should  be  placed  with  the  lower  part  about  eight  feet  above  the 
floor  (allowing  the  room  to  be  twelve  feet  high)  and  in  one  of  the 
warm  sides,  about  four  or  five  feet  from  a  cold  or  exposed  wall. 


THE    SCHOOL   HOUSE.  47 

The  top  of  the  inlet  should  be  curved  so  as  to  throw  the  air 
forward  and  across  the  room  to  the  most  exposed  or  cold  angle  of 
the  two  outer  walls,  the  outlet  being  placed  at  the  floor  level  and 
near  ^ie  inner  or  warm  angle  of  the  room. 

The  air,  on  entering  the  room  though  the  inlet  opening  (which 
should   be   covered   by  a   grill   of  about  one-eighth-inch  wire~0f~ 
diamond  mesh  pattern,  the  mesh  being  about  one  and  one-half  to  two 
inches  long  at  its  greatest   dimension,  and  set  in  a  channel  iron 
frame)  passes  first  forward  and  upward  and  spreads  across  the  ceil- 
ing to  the  outer  wall  of  the  room,  being  at  the  same  time  drawn 
toward  and  down  the  windows  by  the  cooling  effect  of  the  glass 
surface,  continuing  around  the  room  with  a  falling  spiral  movement, 
diffusing    throughout    the    room 
and  gradually  falling  and  drawing 
toward  the  outlet. 

In  a  room  considerably  longer 
than  wide  and  with  three  exposed 
or  cold  walls,  the  inlets  should  be  . 
placed  at  the  same  height  above 
the  floor  as  in  the  preceding  case, 

but  in  this  case  there  should  be 

.    ,   L  mi 

two  inlets  and    one  outlet.     The 

inlets  should  be  in  the  inner  or 
warm  wall,  about  the  same  dis- 
tance from  the  cold  end  walls  as 

FIG.  19. 
in  the  first  instance.     The  outlet 

should  be  placed  at  the  floor  level,  but  as  near  as  practicable  in 
the  center  of  the  inner  or  warm  wall. 

The  entering  air  will  spread  across  the  ceiling  to  the  cold  walls, 
as  in  the  case  of  the  room  with  two  cold  and  two  warm  walls,  but 
a  considerable  part  of  the  two  currents  will  meet  near  the  center  of 
the  longest  outside  wall  and  the  whole  will  be  drawn  down  and 
back  to  the  outlet  near  the  center  of  the  warm  wall. 

In  a  room  having  three  cold  and  one  warm  wall,  but  with  the 
warm  wall  on  one  end  of  the  room,  the  inlet  should  be  placed  about 
eight  feet  above  the  floor  near  the  centre  of  the  warm  wall,  and  the 
outlet  placed  at  the  floor  level,  nearly  under  the  inlet.  The  enter- 
ing air  will  spread  across  the  ceiling  to  the  three  outside  cold  walls, 
where  it  will  fall  and  be  drawn  back  from  all  sides  across  the  room 
to  the  outlet. 

In  a  room  having  one  cold  and  three  warm  walls,  the  inlet  and 
outlet  can  be  placed  either  as  in  the  first  or  last  mentioned  instance. 


48 


THE    SCHOOL   HOUSE. 


(Figures  19  or  21 .)  Good  results  will  be  obtained  either  way,  and 
the  location  can  be  determined  by  considering  which  method  will 
be  best  adapted  to  the  construction  of  the  building  and  the  general 
location  of  other  heat  and  vent  ducts.  . 

A  volume  of  air  heated  from  the  freezing  to  the  boiling  point  of 

water,  barometer  30 
inches,  expands  ap- 
proximately 1/500 
(1/490)  for  each  de- 
gree F.  it  is  raised. 

If    the    air    of    a 
schoolroom  is  40   de- 
grees higher  than  that 
~JU  |      |  /j"""  '"'|?*M|       j"    |      |  '  j  of  the  exterior  air  its 

volume    has   been   in- 


I 


| 


FIG.  20. 


CORRIDOR 

creased  approximately 
2/25 ;    consequently  it 
is  lighter  than  the  exterior  air  and  tends  to  rise. 

A  cubic  foot  of  air  at  60  degrees  F.,  dew  point  40  degrees, 
barometer  30  inches,  will  weigh  534.27  grains. 

A  cubic  foot  of  expired  air  at  95  degrees  F.,  dew  point  85  degrees, 
containing  12.78  grains  of  vapor,  and,  say,  4  per  cent  of  carbonic 
acid,  will  weigh  only  494.12  grains,  or  7.5 
per  cent  less.  This  tendency  to  rise  is  fur- 
ther increased  by  the  heat  given  off  by  the 
body,  which  warms  the  air  in  immediate 
contact  with  it. 

At  first  sight  it  would  seem  easier  to  ven- 
tilate a  schoolroom  by  the  general  upward 
movement  of  the  air,  because  of  its  tendency 
to  rise  when  first  exhaled  from  the  lungs. 

If  the  air  is  admitted  at  the  floor  and  taken 
out  at  the  ceiling  there  is  established  a 
current  between  the  inlet  and  the  outlet, 
leaving  the  foul  air  in  some  parts  of  the 
room  almost  unmoved,  and  only  slowly  and 
partly  drawn  into  the  current. 

Another  objection  to  this  method  of  ventilation  is  the  difficulty 
of  properly  heating  a  schoolroom  by  it.  The  great  loss  of  heat 
necessitated  thereby  calls  for  the  consumption  of  a  much  greater 
quantity  of  fuel.  The  hot  air  is  drawn  off  rapidly  from  the  top, 
while  the  cold  air  remains  at  the  bottom  of  the  room. 


FIG.  21. 


THE    SCHOOL    HOUSE.  49 

From  whatever  point  the  warm  fresh  air  is  admitted  to  the 
schoolroom,  it  rises  at  once  to  the  ceiling,  and  the  sooner  it  reaches 
that  point  without  being  contaminated  the  better  it  will  be. 

By  the  law  of  diffusion  of  gases  the  expired  air  would  in  time 
undoubtedly  be  diffused  throughout  the  whole  room,  as  would  also 
the  poisonous  nitrogenous  matter  exhaled  from  the  lungs  and  bodies. 

By  exhausting  the  foul  air  from  the  bottom  a  downward  move- 
ment of  the  warm  air  entering  at  the  top  of  the  room  is  maintained, 
and  as  the  poisonous  products  of  respiration  must  be  diluted  and 
removed  by  the  introduction  of  pure  air,  a  circulation  within  the 
room  is  maintained  which  will  produce  the  required  results. 

If  we  make  a  careful  inspection  of  the  course  of  hot  air 
admitted  through  a  register  in  the  floor  we  will  see  that  the  current 
of  hot  air  goes  directly  to  the  ceiling,  and  that  a  portion  of  the 
surrounding  cooler  air  is  carried  up  with  it  by  friction,  and  that 
this  air  was  drawn  from  near  the  floor.  The  air  thus  carried  up 
was  foul  air,  and  should  have  been  carried  off  through  the  vent  duct. 

The  question  of  admitting  the  fresh  air  at  the  top  of  the  room 
is  not  determined  by  the  natural  movement  of  carbonic  acid  or  any 
other  impurity,  or  by  the  gravity  or  weight  of  the  air  as  it  comes 
from  the  lungs. 

In  cold  weather  the  fresh  air  must  be  warmed  to  a  number  of 
degrees  above  the  temperature  at  which  we  wish  to  have  the  room 
at  the  breathing  line.  Heated  air  will  go  to  the  top  of  the  room, 
no  matter  where  we  admit  it,  and  its  distribution  will  begin  there. 
By  leading  it  there  in  pipes  or  flues  we  avoid  carrying  up  dust  and 
foul  air  with  it,  and  we  can  locate  the  inlets  and  direct  the  flow  of 
air  so  as  to  distribute  it  more  evenly  than  if  we  admit  it  at  the 
floor.  The  air  will  spread  over  the  ceiling  and  be  drawn  to  the 
outer  walls  by  the  falling  current  caused  by  cooling  on  the 
windows  and  walls.  It  then  descends  to  the  floor,  and  may  be  best 
taken  out  at  the  bottom  of  the  room. 

Wherever  there  is  any  attempt  at  a  proper  system  of  ventilation 
in  a  schoolhouse,  the  walls  and  ceiling  should  be  made  as  impervi- 
ous as  practicable  both  to  air  and  heat. 

The  ceiling  of  an  ordinary  schoolroom  contains  about  nine 
hundred  square  feet  of  surface,  and  generally  consists  only  of  laths 
and  a  coat  of  mortar.  In  the  attic  there  is  frequently  only  a  single 
floor  over  the  ceiling  of  the  room  below,  and  frequently  no  floor 
at  all. 

With  the  temperature  of  the  air  at-  the  top  of  the  room  from 
80  to  90°  F.,  and  that  of  the  attic  at  thirty  degrees,  or  lower,  as  it 


50  THE    SCHOOL    HOUSE. 

may  be  on  a  cold  day,  it  is  easy  to  see  what  an  amount  of  warm 
fresh  air  is  lost.  This  is  particularly  noticeable  in  the  plenum 
method. 

The  objection  has  been  made  to  the  exhaust  system  of  ventilation 
that  the  air  is  drawn  into  the  room  from  every  crevice  in  the  walls, 
floor  and  ceiling,  and  also  from  the  corridors  and  clothes  rooms. 

The  objection  can  also  be  made  to  the  plenum  system  that  the 
impure  air  is  driven  out  at  every  crevice  and  opening,  thus  possi- 
bly forming  accumulations  of  foul  matter  and  disease  germs  in 
places  that  cannot  be  reached  to  be  cleaned ;  also  that  a  consider- 
able part  of  the  warm  fresh  air  which  enters  at  the  inlet  at  a 
higher  temperature  than  at  the  breathing  line  escapes  through  the 
ceiling  and  walls  before  it  has  circulated  and  reached  the  breathing 
plane,  thereby  causing  a  loss  of  heat  that  could  be  utilized  within 
the  room. 

With  the  plenum  system  there  is  always  a  leakage  of  air  from 
the  room,  as  there  also  is  with  a  gravity  system  when  the  exhaust 
is  insufficient,  and  if  this  leakage  takes  place  from  air  at  90  to  100 
degrees  it  is  evident  that  more  heat  will  be  lost  than  from  air  at 
70  degrees. 

There  is  little  difficulty  in  forcing  4000  cubic  feet  of  air  per 
minute  with  a  plenum  fan  into  an  ordinary  schoolroom  when  the 
outlet  is  closed  and  windows  and  doors  made  as  tight  as 
practicable,  and  hardly  a  perceptible  rise  in  the  barometer  can  be 
noted.  This  will  show  the  effect  of  leakage. 

In  some  cases,  especially  where  fans  or  blowers  are  used,  as  in 
the  plenum  system,  to  force  air  into  a  schoolroom,  and  where  the 
exhaust  is  very  deficient,  there  is  a  tendency  to  force  the  air  out  of 
the  room  as  it  falls  on  the  cool  walls  and  also  through  the  ceiling. 
As  the  warm  air  goes  directly  to  the  top  of  the  room  and  at  least 
three-quarters  of  the  leakage  is  above  the  breathing  plane,  a  large 
quantity  of  the  fresh  air  will  not  reach  the  pupils. 

As  the  result  of  many  observations  the  writer  is  led  to  believe 
that  a  schoolroom  supplied  with  1,500  cubic  feet  of  air  per 
minute,  with  properly  located  fresh  warm-air  inlets  and  foul-air 
vent  flues,  will  have  the  air  at  the  breathing  plane  kept  as  pure  as 
it  will  when  supplied  with  2,500  cubic  feet  per  minute  with  no 
proper  provisions  for  circulating  and  removing  the  air. 

The  economy  of  heating  and  forcing  this  extra  1 ,000  cubic  feet 
of  air  into  a  room  has  not  yet  been  satisfactorily  explained. 

Many  persons  who  admit  the  necessity  of  supplying  a  large 
quantity  of  air  for  ventilation  fail  to  appreciate  the  importance  of 


THE    SCHOOL   HOUSE.  51 

the  work  done  by  the  ventilating  duct  or  [chimney.  While  they 
acknowledge  the  good  work  done  by  an  open  fireplace  in  removing 
foul  air  from  a  room,  they  apparently  do  not  appreciate  the  fact 
that  the  fireplace  takes  the  air  from  the  bottom  of  the  room.  The 
ventilating  duct  opening  from  the  bottom  of  the  room  works  in  the 
same  way,  and  when  properly  located  will  do  the  work  with  far" 
less  expenditure  of  fuel  than  the  open  fireplace. 

It  has  been  the  experience  of  the  writer  that  when  a  well-adjusted 
combination  of  the  plenum  and  exhaust  systems  is  installed  in  a 
school  building,  more  economical  and  satisfactory  results  are 
obtained  than  by  the  use  of  either  system  independently. 

When  the  exhaust  is  a  little  in  excess  of  the  plenum,  say  about 
five  per  cent,  the  heat  that  is  lost  by  leakage  by  the  plenum  method 
is  utilized  to  warm  the  air  drawn  into  the  room  through  the  outer 
walls,  but  in  so  many  small  places  that  uncomfortable  drafts  are 
not  produced. 

When  the  corridors,  clothing  and  sanitary  rooms  are  properly 
ventilated  there  is  little  danger  of  foul  air  reaching  the  class-rooms 
from  such  sources.  This  is  at  variance  with  the  recommendations 
of  many  persons,  but  it  is  the  experience  of  the  writer  in  making 
many  hundred  tests  of  the  heating  and  ventilation  of  schoolrooms. 

The  subject  of  leakage  of  air  and  heat  has  not  apparently  received 
the  attention  from  heating  and  ventilating  engineers  which  it 
requires.  In  certain  cheaply  constructed  buildings,  where  a  very 
strong  exhaust  was  in  use,  the  writer  has  frequently  found  twice  and 
sometimes  three  times  as  much  air  going  out  at  the  outlet  as  was  com- 
ing in  at  the  inlet.  This  is  excessive,  and  should  be  guarded  against 
by  proper  adjustment  of  dampers  and  heat  in  the  exhaust  flues. 

In  some  of  the  mechanical  systems  of  heating  and  ventilation  in 
use  in  school  buildings  the  velocity  of  the  air  at  the  inlets  is  too 
great  and  the  size  of  the  pipes  or  ducts  is  too  small.  Six  feet 
velocity  per  second  at  the  inlet  is  enough,  and  five  feet  per  second, 
or  three  hundred  feet  per  minute,  is  .better,  although  in  some  cases > 
where  air  is  brought  into  high-studded  rooms  over  eight  feet  from 
the  floor,  a  velocity  of  seven  feet  per  second  is  not  objectionable. 

In  arranging  for  an  air  supply  for  any  system  of  heating  and 
ventilation  the  number  of  cubic  feet  of  air  to  be  supplied  per 
minute,  divided  by  300,  will  give  the  area  in  square  feet  for  the 
pipe  or  flue. 

Uncomfortable  drafts  will  be  caused  if  the  air  is  brought  into 
the  room  at  too  great  a  velocity,  no  matter  whether  by  a  gravity  or 
a  mechanical  system. 


52  THE  SCHOOL   HOUSE. 

Air  may  be  forced  through  a  main  supply  pipe  at  a  velocity  of 
800  or  1 ,000  feet  per  minute  by  a  fan,  or  at  even  a  greater  velocity 
by  the  expenditure  of  additional  power,  which,  however,  is  not 
always  true  economy ;  but  the  risers  or  ducts  leading  to  the  rooms 
should  be  designed  to  admit  the  air  into  the  room  at  not  over  360 
feet  average  velocity  per  minute. 

Taking  a  small  riser  from  the  main  duct  and  increasing  the  area 
at  the  entrance  into  the  room  will  not  give  the  best  results. 

There  should  be  a  steady  and  certain  outflow  of  vitiated  air 
through  the  extraction  flues.  It  will  not  do  to  have  back  drafts. 
As  before  intimated,  all  ducts  carrying  vitiated  air  are  likely  to 
become  coated  with  foul  matter.  There  should  be  no  possibility 
of  any  return  of  this  matter  to  the  rooms. 

With  properly  constructed  vent  ducts  or  aspirating  chimneys  there 
need  not  be  a  back  draft  under  any  conditions  of  wind  or  temperature. 

Every  building  constitutes  a  problem  by  itself,  to  be  solved  only 
after  a  careful  study  of  all  the  conditions  presented,  and  then  only 
with  a  knowledge  of  the  principles  of  ventilation  and  heating,  and 
the  mechanical  skill  and  experience  requisite  for  a  practical  appli- 
cation of  this  knowledge  to  the  work  in  hand. 

Every  schoolhouse  and  public  building  should  be  planned  with  a 
view  to  a  thorough  system  of  heating  and  ventilation. 

Heating  and  ventilation  are  closely  connected,  and  should  be 
planned  at  the  same  time. 

In  the  construction  of  schoolrooms,  beams  or  projections  below 
the  ceiling  should  be  carefully  avoided  to  prevent  the  deflection  of 
the  current  of  air  from  the  inlet,  and  to  avoid  causing  uncomforta- 
ble drafts.  If  beams  project  down  below  the  ceiling  and  are  at 
right  angles  to  the  entering  air  current  the  air  will  be  deflected  and 
strike  the  heads  of  the  occupants  of  the  seats  a  short  distance 
below  and  beyond  the  beam.  If  the  room  is. .being  cooled  off  or 
the  temperature  of  the  entering  air  is  lower  than  that  of  the  room, 
the  uncomfortable  drafts  will  be  very  apparent. 

If  the  inlet  is  between  two  beams  parallel  to  the  direction  of  the 
current  of  the  incoming  air,  or  between  a  beam  parallel  with  the 
outer  wall  and  the  wall  itself,  the  air  will  pass  along  between  the 
parallel  beams  or  between  the  beam  and  the  wall  to  the  outer  wall 
opposite  the  inlet  without  spreading  across  the  ceiling  properly. 
In  such  cases  an  undesirable  difference  of  temperature  will  be  noted 
in  various  parts  of  the  room. 

In  high-studded  assembly  halls,  usually  placed  in  the  upper  story 
of  a  large  school  building,  it  is  advisable  that  additional  ventilators 


THE    SCHOOL   HOUSE.  53 

be  placed  in  the  ceiling  to  carry  off  an  excess  of  heat  or  an  accumu- 
lation of  foul  air  at  the  top  of  the  room,  which  is  too  high  to  be 
conveniently  ventilated  entirely  by  the  vent  openings  at  the  floor 
level.  These  ceiling  ventilators  are  not  intended  to  be  used  at  all 
times,  but  only  as  the  special  occasion  may  require.  They  should_ 
preferably  pass  up  through  the  roof,  or  they  can  be  connected  with 
the  ducts  which  take  the  air  from  the  bottom  of  the  room. 

Where  gas  lights  are  used  the  ceiling  ventilators  should  be  placed 
^over  the  groups  of  burners. 

Placing  the  stacks  of  indirect  radiators  or  the  furnace  in  the 
basement  in  a  wrong  position,  at  the  base  of  the  warm  air  shaft,  is 
a  source  of  cold  and  uncomfortable  drafts  in  the  room. 

The  heating  apparatus  should  always  be  placed  in  such  a 
position  that  the  warm  air  will  pass  up  on  the  front  or  room  side 
of  the  shaft  and  the  cold  air  used  for  mixing  will  pass  up  on 
the  rear  side.  If  placed  so  that  the  warm  air  comes  up  on  the 
rear  side  of  the  shaft  cold  drafts  will  surely  be  felt. 

Deflectors  and  diffusers,  which  are  generally  useless,  costly  and 
unsightly  devices,  placed  in  front  of  the  warm  air  inlets  will  not 
prevent  these  troublesome  cold  drafts. 

A  mixing  damper,  which  is  a  device  placed  near  the  bottom  of 
the  warm-air  shaft  to  regulate  the  temperature  of  the  incoming  air 
without  materially  diminishing  the  quantity,  is  of  great  service. 

When  it  is  desired  to  have  an  entire  supply  of  warm  air  the 
chain  leading  from  the  mixing  damper  to  the  schoolroom  is  let  out, 
and  the  mixing  damper  falls  back  and  prevents  the  entrance  of  cold 
air  into  the  shaft.  When  it  is  desirable  to  cool  the  incoming  air 
the  chain  is  pulled  a  little,  and  cold  air  is  admitted  to  mingle  with 
the  warm  air  in  the  shaft. 

This  damper  should  not  be  changed  from  all  warm  to  all  cold, 
or  from  all  cold  to  all  warm  air,  by  one  movement.  If  this  is  done 
the  room  temperature  may  be  too  quickly  changed  and  the  room 
made  too  cold  or  too  warm,  and  a  constant  variation  of  the  tempera- 
ture of  the  air  in  the  room  will  follow,  often  accompanied  by  cold 
drafts  in  very  cold  or  windy  weather. 

When  it  becomes  necessary  to  change  the  temperature  of  the 
room  the  mixing  damper  chain  should  be  gradually  let  out  or  pulled 
in;  about  one  inch  or  less  at  a  time  will  generally  be  sufficient. 

When  the  heating  apparatus  is  properly  located  at  the  base  of 
the  warm-air  shaft  the  warm  air  will  pass  up  on  the  front  and 
the  cold  air  on  the  rear  part  of  the  shaft,  the  cold  air  being  drawn 
up  and  mixed  by  the  ascending  current  of  warm  air.  If  the  two 


54  THE    SCHOOL    HOUSE. 

currents  are  not  thoroughly  mixed  in  the  shaft  before  the  direction 
of  the  air  currents  is  changed  from  a  perpendicular  to  a  nearly 
horizontal  direction  to  flow  into  the  room,  the  warm  air  will  be  on 
the  lower  side  of  the  stratum  of  fresh  air  and  will  buoy  up  and 
diffuse  the  cold  air. 

If,  however,  the  cold  air  is  on  the  front  side  of  the  shaft,  when 
the  direction  of  the  current  is  changed  the  cold  air  will  be  on  the 
bottom  of  the  stratum  of  fresh  air,  and  being  colder  than  the  air 
in  the  room,  will  fall  as  an  uncomfortable  draft  on  the  occupants  of 
the  seats  in  front  of  the  inlet.  These  cold  drafts  are  usually  more 
noticeable  at  from  eight  to  twelve  feet  in  front  of  the  inlet  than  in 
other  parts  of  the  room. 

An  excessive  outflow  of  air  through  the  outlet  duct  is  not  desira- 
ble, as  the  air  currents  are  sometimes  deflected  or  short  circuited, 
and  the  heat  and  fresh  air  are  wasted  before  having  done  the  work 
required  in  the  rooms. 

This  is  particularly  the  case  in  very  cold  or  windy  weather.  It 
also  causes  an  excessive  leakage  of  cold  air  into  the  room,  and 
sometimes  reduces  the  temperature  of  the  air  in  the  room  to  an 
undesirably  low  point. 

Every  foul-air  outlet  should  be  provided  with  a  galvanized-iron 
curved  damper,  or  at  least  a  roller-shade  curtain,  to  regulate  the 
outflow  of  air. 

Judgment  must  be  used  by  the  janitor  and  teacher  in  the  manage- 
ment of  these  dampers.  During  mild  weather  the  damper  should 
be  wide  open,  but  during  very  windy  or  cold  weather  it  should  be 
partly  but  never  fully  closed  while  the  room  is  occupied. 

The  proper  management  of  these  outlet  dampers  is  a  matter  that 
should  be  fully  and  carefully  explained  to  the  teachers  and  janitors. 

In  cold  weather,  when  the  room  is  not  occupied,  the  outlet 
dampers  should  be  closed  in  order  to  prevent  an  undue  loss  of  heat 
from  the  room.  While  a  schoolroom  should  be  thoroughly  venti- 
lated during  school  hours  and  after  the  school  has  been  dismissed, 
the  outlet  damper  should  be  left  open  long  enough  to  flush  out  the 
room  with  fresh  air,  yet  to  continue  the  ventilation  the  whole 
twenty-four  hours  will  cause  an  unnecessary  expenditure  of  fuel 
which  would  be  extremely  wasteful. 

In  some  cases  gossamer  rubber-cloth  flap-check  valves  have  been 
placed  at  the  outlet  opening.  These  things  are,  however,  seldom 
used  by  the  most  successful  heating  and  ventilating  engineers  and 
contractors,  as  they  are  often  worse  than  useless.  It  takes  a  strong 
current  of  air  to  open  them,  and  this  means  an  expenditure  of 


THE    SCHOOL    HOUSE.  55 

power,  either  mechanical  (by  a  fan)  or  of  heat,  which  is  a  need- 
less waste.  Being  automatic  and  intended  to  prevent  back  drafts 
they  are  liable  to  close  while  school  is  in  session  and  shut  off  the 
outflow  of  foul  air,  or  they  may  open  at  night  or  when  the  school 
is  not  in  session  and  cause  a  loss  of  heat  from  the  building  and  an 
unnecessary  cooling  of  the  rooms.  When  a  strong  wind  is  blowing 
they  often  flap  open  and  shut,  making  a  noise  which  is  very  objec- 
tionable in  a  schoolroom.  With  a  properly  designed  and  located 
vent  shaft,  having  either  a  fan  or  heat  to  cause  the  outflow  of  foul 
air,  and  with  a  damper  to  close  when  ventilation  is  not  required, 
there  should  be  no  use  for  such  worthless  and  objectionable  things 
as  gossamer  flap-valves  in  a  vent  duct. 

Many  persons  advocate  the  plenum  system,  in  which  the  air  is 
forced  into  a  schoolroom  and  the  pressure  in  the  room  is  outward, 
rather  than  the  exhaust  system. 

In  factories  and  places  where  machinery  and  belts  keep  the  air 
in  motion  and  well  stirred  and  mixed,  and  where  heat  is  more  to  be 
considered  than  the  amount  of  air  for  ventilation,  the  plenum  system 
is  well  adapted  to  the  purpose.  A  hot-blast  system  which  will 
produce  excellent  results  in  a  factory  or  large  workshop,  will  not 
give  the  desired  results  in  a  schoolroom. 

In  school  buildings  and  audience  halls,  where  a  large  quantity  of 
moderately  warmed  air  is  required  for  ventilation,  it  has  been  the 
writer's  experience  that  a  judicious  combination  of  the  plenum  and 
exhaust  systems  gives  the  best  results. 

Where  the  plenum  system  alone  is  used  and  no  heat  or  mechani- 
cal means  employed  for  exhausting  the  foul  air,  the  results  have 
not  been  as  satisfactory  as  where  the  two  systems  were  combined. 

In  the  plenum  system  the  air,  being  under  a  slight  pressure  in  all 
parts  of  the  room,  is  forced  out,  not  only  at  the  vent  openings  but 
through  every  crack  and  opening,  and  the  circulation  is  not  as  good 
as  in  a  combination  system,  and  a  greater  amount  of  heat  is  required. 

Many  heating  and  ventilating  systems  would  have  proven  failures 
had  it  not  been  for  the  amount  of  air  supplied  by  leakage  into  the 
rooms. 

The  writer  has  found,  when  measuring  the  air  supply  in  school- 
rooms, that  under  certain  conditions  from  50  to  300  per  cent  more 
air  was  going  out  at  the  outlet  than  was  coming  in  at  the  fresh-air 
inlet,  the  difference  being  made  up  by  the  inward  leakage.  In 
many  cases  where  a  sufficient  supply  of  air  had  not  been  provided 
the  pupils  would  have  suffered  had  it  not  been  for  this  inward 
leakage  of  fresh  air.  Even  with  such  a  great  difference  between 


56  THE    SCHOOL    HOUSE. 

the  air  supplied  and  the  air  exhausted,  the  temperature  did  not  vary 
but  three  or  four  degrees,  as  was  shown  by  thermometers  placed 
on  the  pupils'  desks  at  the  four  corners  of  the  room  and  also  on  the 
teacher's  desk. 

These  differences  have  been  noticed  in  both  the  mechanical  and 
gravity  systems  of  supply,  and  are  not  confined  wholly  to  wooden 
buildings  of  cheap  construction. 

A  person  not  conversant  with  the  facts  may  well  be  inclined  to 
doubt  the  correctness  of  this  statement,  but  a  series  of  careful 
tests  will  convince  him  of  its  accuracy. 

The  force,  and  direction  of  the  prevailing  winds  in  the  district 
where  the  building  is  located  should  also  receive  careful  considera- 
tion from  the  heating  and  ventilating  engineer  and  the  architect.  In 
Massachusetts  the  prevailing  winds  in  winter  are  from  the  northwest. 

Where  air  is  forced  by  a  fan  through  a  long  duct  against  the 
prevailing  winds,  and  where  there  are  several  branches  taken  off, 
suitable  allowance  must  be  made  in  the  size  of  the  ducts,  and  at 
each  branch  where  it  leaves  the  main  duct  suitable  adjusting 
switch-dampers  or  reducers  should  in  all  cases  be  provided. 

Theoretically,  the  size  of  the  duct  fo  carry  a  certain  amount  of 
air  at  a  given  velocity  to  a  given  point  may  be  easily  calculated ; 
but  the  engineer  or  architect  must  not  be  surprised  to  find  his 
calculation  considerably  out  of  the  way  some  day  when  a  cold  and 
strong  wind  is  blowing,  if  the  prevailing  direction  of  the  wrind  has 
not  been  taken  into  account  when  designing  the  system. 

The  discharge  from  a  ventilating  duct,  even  when  a  good  fan  is 
provided,  should  never  be  directly  out  from  the  side  or  end  of  a 
building,  when  it  can  be  possibly  avoided.  The  writer  has  seen 
cases  where  the  discharge  has  been  out  from  the  side  of  the  build- 
ing against  a  very  strong  wind,  and  when  a  good  fan  was  running 
at  a  high  speed  no  air  would  be  discharged  from  the  outlet  pipe. 
The  strong  wind  blowing  directly  into  the  discharge  pipe  would 
more  than  neutralize  the  power  of  the  fan. 

The  vent-duct  opening  should  be  up  and  through  the  top  of  the 
building  whenever  possible  to  have  it  so  placed. 

If  on  account  of  the  construction  of  the  building  it  is  not 
practicable  to  carry  the  vent  opening  to  the  top,  but  is  necessary  to 
discharge  from  the  side  or  end,  a  shield  or  guard  should  be  pro- 
vided to  deflect  the  wind  and  prevent  it  blowing  directly  into  the 
vent  opening. 

A  strong  wind  blowing  across  the  top  of  a  chimney  or  venti- 
lating duct  will  produce  an  additional  outflow  of  air. 


THE    SCHOOL    HOUSE.  57 

To  illustrate  this  action,  take  a  glass  tube  about  three-eighths  of 
an  inch  diameter  and  about  five  or  six  inches  long,  open  at  both 
ends ;  in  the  tube,  about  two-thirds  of  the  distance  from  the 
bottom  to  the  top  when  the  tube  is  held  in  a  perpendicular  position, 
place  a  light  bit  of  cotton  fibre  or  similar  material,  then  holding 
the  tube  before,  but  not  too  close  to  your  mouth,  give  a  strong  puff 
from  the  lungs.  The  cotton  will  be  forced  up  and  out  the  tube 
and  fly  off  in  the  direction  of  the  current  of  air  from  the  lungs. 

To  illustrate  the  effect  of  wind  striking  a  projection  on  or  near 
the  top  of  the  chimney  or  vent  shaft,  use  the  same  tube  and  bit  of 
cotton,  but  hold  the  hand  or  some  flat  article,  such  as  a  book  or 
piece  of  board,  in  front  of  and  beyond  the  top  of  the  perpendicular 
tube ;  a  strong  puff  from  the  lungs  will  cause  the  air  to  strike  the 
obstruction  and  be  deflected  down  into  the  tube,  carrying  the  cotton 
out  at  the  bottom. 

It  sometimes  happens  that  one  vent  flue  in  a  school  building  will 
cause  trouble  by  having  a  down  draft,  while  the  other  will  be 
doing  satisfactory  work.  If  an  inspection  is  made  of  the  top  of 
the  flue  it  will  probably  be  seen  that  some  projection  is  above  or 
against  one  side  or  end  of  the  top,  against  which  the  wind  strikes 
and  is  deflected  down  the  vent  flue. 

The  practice  of  extending  the  smoke  flue  up  above  the  level  of 
other  parts  of  the  same  stack  should  be  avoided.  Unless 
absolutely  called  for  by  some  special  construction  of  the  building 
as  regards  towers,  etc.,  the  top  of  the  smoke  and  vent  flues,  if 
constructed  of  masonry,  should  not  be  capped  or  hooded  over. 
The  danger  of  wrater  or  snow  going  down  the  brick  flue  is  very 
small.  The  bricks,  being  porous,  absorb  the  moisture,  which  is 
soon  evaporated  by  the  current  of  warm,  dry  air  passing  up  the  flue. 

Vent  flues  and  chimneys  should  when  practicable  be  carried  well 
above  the  highest  part  of  the  ridge. 

The  writer  recalls  a  building  designed  by  a  well-advertised  firm 
of  architects  in  which  the  system  of  heating  and  ventilation  was 
designed  by  a  heating  and  ventilating  engineer  who  has  frequently 
been  quoted  as  an  expert. 

The  vent  shaft  was  of  large  dimensions ;  in  it  were  the  venti- 
lating openings  from  several  rooms,  and  there  were  no  divisions  or 
withes  in  the  shaft.  The  top  was  considerably  below  the  ridge  of 
the  building,  and  was  capped  with  blue-stone  flagging.  There 
were  two  good-sized  openings  on  each  side  under  the  cap. 

A  considerable  quantity  of  steam-pipe  was  placed  in  a  coil 
around  the  sides  of  the  shaft  and  located  just  above  the  floor  of  the 


58  THE    SCHOOL   HOUSE. 

first  story  of  the  building.  Flap  valves  were  placed  over  the  room 
outlets  to  prevent  back  drafts.  When  the  wind  was  from  a  certain 
direction  these  flap  valves  were  kept  closed  by  the  down  drafts, 
thereby  shutting  off  the  ventilation  from  the  schoolrooms. 

Complaints  of  bad  ventilation  continued  to  be  made.  More 
steam  pipes  were  put  in  the  shaft  till  about  300  square  feet  of  radi- 
ating surface  had  been  put  in  the  shaft. 

The  complaints  continued,  and  the' writer  was  called  by  the 
school  authorities  to  see  what  was  the  trouble.  The  examination 
was  made  on  a  cold  day  when  a  strong  wind  was  blowing.  The 
steam  was  turned  on  full  head  in  the  vent-coil  heaters  (the  boiler 
pressure  being  ten  pounds  by  the  gauge). 

Commencing  in  the  basement  at  the  lowest  opening  into  the 
vent  shaft,  the  flap  valves  were  found  to  be  closed,  and  on  lifting 
them  and  placing  an  anemometer  in  front  of  the  opening  so  made, 
the  air  was  found  to  be  coming  down  and  into  the  room  at  a 
velocity  of  over  500  feet  per  minute  and  at  a  temperature  of  28 
degrees  F. 

The  school  authorities  wrere  advised  to  remove  the  blue-stone 
cap,  brick  up  the  openings  in  the  shaft,  and  carry  it  above  the 
ridge ;  also  to  remove  the  flap  valves.  This  was  done,  although 
the  architects  protested  that  it  would  injure  the  architectural 
appearance  of  the  building.  Galvanized  iron  dampers  wrere  placed 
at  the  room  outlets  where  the  flap  valves  had  been  removed,  and 
part  of  the  steam-pipe  was  taken  out  of  the  shaft. 

No  trouble  was  afterward  found  in  having  a  good  outflow  of  foul 
air  from  the  schoolrooms,  and  no  back  drafts  were  noticed. 

Where  galvanized  iron  vent  flues  are  used  it  is  well  to  cover  them 
with  a  cap  which  should  project  well  beyond  the  sides  of  the  duct. 
It  is  essential  that  sufficient  clearance  space  be  allowed  between  the 
cap  and  the  top  of  the  vent  flue.  Howr  frequently  we  see  flues  of 
ample  size  that  have  a  cap  close  down  to  the  top  of  the  flue  with 
but  little  chance  for  the  air  to  escape. 

It  should  be  remembered  that  the  openings  on  all  four  sides  are 
not  always  available,  and  that  only  about  one-half  of  the  area  can 
be  considered  as  effective,  that  is,  the  leeward  half,  or  the  part  in 
the  direction  the  wind  is  going. 

Whether  the  warm-air  inlets  and  foul-air  outlets  are  properly 
located  can  be  determined  by  wrapping  in  a  piece  of  paper  dipped 
in  nitrate  of  potash  and  then  dried,  or  in  a  piece  of  tissue  paper,  a 
small  tablespoonful  of  gunpowder,  placing  it  on  a  piece  of  sheet 
metal  or  board  held  about  twro  feet  in  front  of  the  warm-air  inlet, 


THE   SCHOOL   HOUSE.  59 

setting  fire  to  the  paper  and  watching-  the  circulation  and  diffusion 
of  the  smoke. 

A  sponge  saturated  with  ammonia  and  held  over  a  dish  of  hydro- 
chloric (muriatic)  acid  will  also  show  the  circulation  of  air,  but 
is  not  as  convenient  or  desirable  as  the  powder  smoke  test. 

The  down  or  coma  of  the  milkweed  or  thistle  can  also  be  used 
to  show  the  movement  of  air  currents  in  a  room,  but  not  as  fully 
as  the  powder  smoke  test. 

The  movement  of  the  air  currents  by  the  powder  smoke  test  may 
be  best  observed  by  taking  a  position  at  the  inner  angle  of  the 
room,  so  selected  that  the  light  .from  the  windows  in  the  outer 
walls  will  best  enable  the  observer  to  see  the  movement  of  the 
smoke. 

The  action  of  open  windows  on  the  circulation  of  air  in  a  room 
wrill  become  apparent  by  using  the  powder  smoke  test. 


CHAPTER    IV. 


AIR   SUPPLY   FOR   SCHOOL   ROOMS. 

THE  following  tables  give  the  average  results  of  a  number 
of  tests  of  the  air  supply  in  schoolrooms  made  by  the 
Massachusetts   inspectors  in  different   parts   of  the   state 
in  buildings  of  different  size  and  construction,  of  wood  or  brick, 
under  different  conditions  of  temperature,  wind,  weather,  humidity 
and  barometric  pressure. 

These  results  are  not  to  be  considered  as  what  is  theoretically 
required,  but  such  as  may  be  expected  in  actual  practice  in  school- 
house  ventilation. 

The  inside  temperatures  were  taken  at  the  breathing  plane,  at 
the  four  corner  desks  and  at  the  teacher's  desk  at  the  same  time. 


TABLE    3. 
AVERAGE  RESULTS  OF  TESTS  MADE  IN  100  VENTILATED  SCHOOLS. 


Temperature,  Degrees  F. 

Velocity  at  Inlet, 
Feet  per  Minute. 

Net  Available 
Area  of  Inlet, 
Square  Feet. 

Cubic  Feet  of  Air 
Per  Minute 
Supplied  at  Inlet. 

Outside. 

Inside. 

At  Inlet. 

34.26 

69.69 

93.78 

399.39 

4.439 

1,772.892 

TABLE  4. 

AVERAGE  RESULTS  OF  TESTS  MADE  IN  500  VENTILATED   SCHOOLS  WHEN 

OUTSIDE  TEMPERATURE  WAS  BELOW  40°  F.      (FRACTIONS  OMITTED 

IN  THIS  CASE.) 


Temperature,  Degrees  F. 

Velocity  at  Inlet, 
Feet  per  Minute. 

Net  Available 
Area  of  Inlet, 
Square  Feet. 

Cubic  Feet  of  Air 
per  Minute 
Supplied  at  Inlet. 

Outside. 

Inside. 

At  Inlet. 

25 

70 

92 

377 

4 

1,508 

THE    SCHOOL    HOUSE. 


61 


TABLE  5. 
AVERAGE  RESULTS  OF  TESTS  MADE  IN  500  VENTILATED  SCHOOLS. 


Temperature,  Degrees  F. 

Velocity  at  Inlet, 
Feet  per  Minute. 

Net  Available 
Area  of  Inlet, 
Square  Feet. 

Cubic  Feet  of  Air 
per  Minute 
Supplied  at  Inlet. 

Outside. 

Inside. 

At  Inlet. 

40.01 

70.6 

93.3 

355.4 

4 

1,421.6 

TABLE    6. 
AVERAGE  RESULTS  OF  TESTS  IN  1,040  VENTILATED  SCHOOLS. 


Temperature,  Degrees  F. 

Velocity  at  Inlet, 
Feet  per  Minute. 

Net  Available 
Area  of  Inlet 
Square  Feet. 

Cubic  Feet  of  Air 
per  Minute 
Supplied  at  Inlet. 

Outside. 

Inside. 

At  Inlet. 

37.9 

70.2 

93.3 

369.6 

4.13 

1,526.488 

These  tests  show  the  amount  and  temperature  of  air  supplied  at 
the  warm-air  inlets,  but  do  not  include  the  additional  amount  of  air 
brought  into  the  room  by  leakage  through  walls,  ceilings,  floors, 
or  through  openings  or  cracks  around  doors  and  windows  when 
the  exhaust  through  the  vent  shafts  was  greater  than  the  supply  at 
the  warm-air  inlets ;  neither  do  they  take  into  consideration  the  air 
forced  out  of  the  room  through  the  same  places  when  the  conditions 
are  reversed  and  the  supply  at  the  inlets  exceeded  the  exhaust  at 
the  vent  openings. 

In  some  cases  the  air  exhausted  through  the  vent  ducts  was  con- 
siderably in  excess  of  the  supply  at  the  inlets,  the  difference  being 
made  up  by  inward  leakage.  In  other  cases  it  was  the  reverse, 
and  outward  leakage  accounted  for  the  difference. 

These  are  average  tests,  and  do  not  include  those  cases  where  a 
great  difference  was  found  between  the  amount  of  air  supplied  at 
the  warm-air  inlet  and  that  extracted  at  the  vent  outlet.  Sometimes 
the  amount  of  air  is  more  than  double  at  the  outlet  the  amount  at 
the  inlet,  or  it  may  be  the  reverse. 

These  cases  occur  in  loosely-constructed  buildings,  or  where 
proper  adjustment  has  not  been  made  of  the  dampers  at  the  outlets 
or  of  the  windows  admitting  air  to  the  cold-air  rooms  where  the 
indirect  radiation  is  located.  They  are  only  mentioned  to  show 
the  necessity  of  good  construction  and  proper  regulation  of  the 
exhaust  and  supply  openings. 


62 


THE    SCHOOL   HOUSE. 


From  a  large  number  of  observations  it  appears  that  in  order  to 
supply  a  schoolroom  with  1,500  cubic  feet  of  air  per  minute  when 
the  temperature  outside  is  30  degrees  F.  we  shall  have  to  introduce 
the  air  at  the  warm-air  inlet  at  about  93  degrees  F.  to  keep  the 
room  at  70  degrees  F.,  at  the  breathing  plane  of  the  pupils,  raising 
the  temperature  of  the  air  63  degrees  F.  Fifteen  hundred  cubic  feet 
of  air  raised  63  degrees  equals  94,500  cubic  feet  raised  one  degree. 

From  the  average  tests  of  a  large  number  of  unventilated  schools 
we  find  that  to  keep  a  schoolroom  at  70°  F.  with  the  outside 
temperature  at  30°  F.,  supplying  500  cubic  feet  per  minute,  we 
shall  have  to  send  the  air  in  at  about  180°  F.  This  is  an  increase 
of  150  degrees  over  the  outside  air. 

Five  hundred  cubic  feet  raised  150  degrees  equals  75,000  cubic 
feet  raised  one  degree. 

Assuming  that  it  costs  the  same  in  each  case  to  raise  a  cubic  foot 
of  air  one  degree  in  temperature,  the  increased  cost  of  furnishing 
1,500  cubic  feet  per  minute  to  a  schoolroom  over  the  old  method 
of  furnishing  500  cubic  feet  per  minute  would  be  about  26  per  cent 

The  cost  of  heating  schoolrooms  varies  considerably  in  actual 
practice,  depending  upon  the  construction  and  location  of  the 
building,  the  system  of  heating  and  ventilation  installed,  and  the 
care  and  judgment  exercised  by  the  janitor. 

A  fair  average  allowance  of  fuel  for  good  ventilation  and  proper 
warming  may  be  considered  as  ten  tons  of  hard  coal  per  school- 
room per  year.  This  includes  all  the  space  within  the  building 
occupied  by  corridors,  basement  and  small  rooms,  in  addition  to 
the  schoolrooms. 

The  following  shows  the  cost  of  heating  eight  schoolhouses  by 
different  methods  during  the  winter  of  1893  and  1894,  and  is 
given  as  showing  the  difference  in  cost  that  may  occur  under 
different  conditions. 

TABLE   7. 


Building. 

Kind  ot 
Heat. 

Ventilation. 

Number  of 
Rooms. 

Cost  of  Fuel 
per  Room. 

1 

Steam 

Combination  of  supply  and  exhaust 

10 

$50.50 

2 

Steam 

Combination  of  supply  and  exhaust 

16 

53.31 

3 

Steam 

Plenum  supply,  no  special  exhaust 

22 

106.00 

4 

Steam 

Plenum  supply,  no  special  exhaust 

12 

108.10 

5 

Furnace 

Combination  of  supply  and  exhaust 

12 

60.75 

6 

Furnace 

Combination  of  supply  and  exhaust 

8 

63.25 

7 

Steam 

No  modern  ventilation 

16 

90.82 

8 

Furnace 

No  modern  ventilation 

13 

63.53 

THE    SCHOOL   HOUSE.  63 

WARM-AIR  DUCTS  OR  FLUES. 

The  proper  location  of  warm-air  inlets  for  supplying  fresh  air  -to 
schoolrooms  is  a  matter  that  should  be  carefully  considered  by  the 
architect  who  plans  the  building  and  also  by  the  heating  and  venti- 
lating engineer  who  designs  the  system  of  heating  and  ventilation. 
This  is  also  referred  to  under  the  head  of  circulation  of  air.  The 
size  or  cross-section  of  the  warm-air  duct  is  another  subject  for 
careful  consideration,  and  is  determined  by  the  amount  of  air  to 
be  supplied,  and  should  be  proportioned  to  the  number  of  persons 
who  are  to  occupy  the  room.  , 

One  of  the  defects  in  the  early  attempts  at  ventilation  was  the 
small  area  of  cross-section  of  the  warm-air  supply  ducts.  With 
the  gravity  system,  when  too  small  ducts  were  used,  it  was 
necessary  that  the  air  be  heated  to  a  very  high  temperature  in  order 
to  give  the  required  velocity  to  obtain  the  amount  desired. 

In  a  mechanical  system,  where  a  fan  is  used  and  the  ducts  are 
not  large  enough,  the  air  will  be  forced  into  the  room  at  too  great 
a  velocity,  sometimes  causing  uncomfortable  drafts.  The  fan  will 
also  require  additional  power  in  order  to  force  the  air  through  the 
small  ducts  at  high  velocity. 

In  a  gravity  system,  the  warm-air  ducts  should  be  of  ample  area 
to  admit  the  air  in  sufficient  quantity  to  meet  the  requirements  of 
mild  weather  when  it  is  only  warmed  to  a  moderate  degree. 

Many  tests  by  the  Massachusetts  inspectors  show  that  the  best 
results  are  obtained  when  the  warm-air  ducts  have  a  cross-sectional 
area  of  24, by  36  inches  (six  square  feet). 

Five  square  feet,  24  by  30  inches,  will  give  fair  results,  but  24 
by  36  inches  is  to  be  preferred.  This  is  for  an  ordinary  school- 
room 28  by  32  by  12  feet,  accommodating  50  persons. 

Class-rooms  a  little  larger  or  smaller  than  the  above  standard,  or 
containing  a  greater  or  less  number  of  persons,  can  have  the  warm- 
air  ducts  proportionally  increased  or  diminished.  In  small  rooms, 
or  in  large  rooms  having  but  fewr  pupils,  or  where  there  is  a  large 
exposed  wall  or  glass  surface,  or  where  no  direct  radiation  is  used, 
a  liberal  allowance  should  be  made  for  the  area  of  the  -warm-air 
ducts 

The  top  of  the  warm-air  duct,  where  it  enters  the  room,  should 
be  curved  to  easily  change  the  direction  of  the  entering  air  from  a 
perpendicular  to  a  nearly  horizontal  direction.  The  interior  of 
brick  warm-air  and  foul-air  ducts  and  flues  should  be  made  as 
smooth  as  practicable,  and  rough  projections  of  mortar  should  not 
be  allowed.  Where  the  expense  can  be  incurred  it  is  advisable  to 


64  THE    SCHOOL   HOUSE. 

cover  the  inside  walls  of  warm-air  ducts  with  a  light  coat  of 
adamant  plaster  or  Portland  cement  to  give  a  smooth  surface  and 
reduce  the  friction. 

Galvanized-iron  ducts  should  be  made  as  tight  as  practicable. 

Ducts  constructed  of  laths  and  plaster,  or  of  expanded  metal 
and  plaster,  should  not  be  used,  as  the  leakage  of  air  through  them 
is  very  great. 

The  inlet  opening  into  the  room  should  be  of  larger  area  than 
the  cross-section  of  the  uptake  duct  in  order  to  allow  for  the 
obstruction  of  the  register  face  or  grill  covering  the  opening,  and 
also  to  allow  for  the  space  at  the  bottom  of  the  opening  where 
there  is  little,  if  any,  inflow  of  warm  fresh  air. 

If  a  wire  grill  is  used  to  cover  the  opening  into  the  room  the 
opening  should  be  at  least  30  by  36  inches  where  the  uptake  is 
24  by  36  inches. 

Where  cast-iron  register  faces  are  used  t'he  opening  should  have 
an  area  of  from  33  to  50  per  cent  larger  than  the  uptake,  on 
account  of  the  reduction  of  the  available  area  and  the  friction  of 
the  register  face.  Cast-iron  register  faces  are  more  expensive  than 
wire  grills,  and,  when  placed  above  the  floor  level,  cannot  be 
recommended  for  covering  warm-air  inlets  or  foul -air  outlets. 

When  two  or  more  stories  of  the  same  building  are  to  be 
supplied  with  warm  air  from  the  same  source,  and  where  the  ducts 
all  lead  from  one  cold-air  room,  it  is  well  to  place  the  duct  for  the 
first  story  nearest  the  cold-air  supply  window.  The  first  story 
duct,  being  of  less  height  than  the  others,  will  have  less  lifting 
power  than  those  to  the  second  and  third  stories,  and,  consequently, 
should  be  placed  where  the  supply  is  largest,  especially  if  the  cold- 
air  room  or  duct  to  the  heater  is  of  limited  capacity.  If  the  duct 
leading  to  the  second  or  third  story  is  placed  nearest  the  source  of 
supply,  being  higher  or  longer  than  the  one  leading  to  the  first 
story  it  will  rob  that  duct  of  its  fair  proportion  of  air. 

The  opening  in  the  duct  where  it  receives  the  warm  air  from  the 
heaters  should  be  but  a  few  inches  above,  or,  better,  on  the  level 
with  the  top  of  the  indirect  radiators  or  directly  from  the  hot-air 
chamber  of  the  furnace. 

The  opening  for  receiving  the  cold  air  for  mixing  and .  reducing 
the  temperature  of  the  warm  air  should  be  at  the  bottom  of  the 
duct  and  of  an  area  equal  at  least  to  the  cross-sectional  area  of  the 
uptake  duct. 

The  mixing  damper  for  regulating  the  temperature  should  be 
hung  at  the  bottom  of  the  warm-air  opening  from  the  heater,  and 


THE    SCHOOL   HOUSE.  65 

should  incline  upward  toward  the  back  of  the  duct.  It  should  be 
operated  from  the  schoolroom  by  means  of  a  stout  chain  and  suitable 
device  for  holding  it  in  any  desired  position. 

It  is  advisable  in  many  cases  to  provide  a  sliding  adjusting  dam- 
per at  the  bottom  of  the  opening  where  the  warm  air  from  the 
heater  enters  the  uptake  duct,  in  order  that  the  supply  of  air  to  the 
different  rooms  may  be  properly  adjusted. 

Theoretically,  the  warm-air  ducts  leading  to  the  upper  rooms 
may  be  of  less  cross-section  than  those  leading  to  the  first  story.  In 
acftial  practice  this  is  seldom  done,  and  the  adjusting  damper  or 
slide  is  used. 

When  a  mechanical  system  is  used  and  the  air  to  the  several 
rooms  is  forced  by  a  blower  or  fan  through  one  or  more  main 
supply  ducts,  and  branches  are  taken  off  for  the  different  rooms,  a 
switch  or  adjusting  damper  should  always  be  provided  at  the  point 
where  the  branch  leaves  the  main  duct,  and  suitable  means  pro- 
vided for  holding  the  switch  damper  in  any  desired  position. 

The  cross-sectional  area  of  each  branch  and  the  reduction  of  area 
in  the  main  duct  as  the  branches  are  taken  off  should  be  calculated 
theoretically,  making  proper  allowance  for  friction,  but  the  switch 
dampers  should  never  be  omitted  if  proper  distribution  of  air  to  the 
several  rooms  is  expected  in  actual  practice. 

The  writer  has  never  seen  entirely  satisfactory  results  obtained 
under  all  conditions  of  wrind  and  temperature  where  the  switch 
dampers  have  been  omitted,  although  the  sizes  of  the  different 
branches  had  been  carefully  designed  according  to  the  best  theo- 
retical rules.  If  a  very  strong  north  or  northwesterly  wind  was 
blowing,  the  switch  dampers  could  be  adjusted  to  meet  the  existing 
conditions ;  but  if  the  wind  was  from  the  south  or  southeast  a 
different  adjustment  of  the  switch  dampers  would  be  required. 

Where  a  fan  or  blower  has  been  used  and  the  ducts  had  not  been 
designed  of  suitable  size  and  the  air  entered  the  room  at  too  high 
a  velocity,  causing  uncomfortable  drafts,  the  writer  has  in  some 
cases  to  a  considerable  extent  overcome  the  difficulty  by  placing 
inside  and  against  the  grill  a  wire  screen  made  of  ordinary  iron 
mosquito  netting.  Where  this  is  used  the  grill  should  be  arranged 
so  that  it  can  be  easily  taken  out  to  clean  the  screen  occasionally. 

Although  this  screen  will  be  an  obstruction  and  require  a  little 
more  power,  yet  it  is  better  than  to  have  the  uncomfortable  drafts. 

This  mosquito-screen  netting  should  only  be  used  where  a 
mechanical  (fan)  'system  is  in  operation,  and  should  not  be  used 
with  a  gravity  system. 


66  THE    SCHOOL    HOUSE. 

ASPIRATING  CHIMNEYS  AND  VENT  FLUES. 

The  power  of  an  aspirating  chimney  or  vent  flue  to  remove  a 
given  quantity  of  air  from  a  room  depends  upon  its  area  .or  cross- 
section,  its  height,  the  difference  between  the  external  and  internal 
temperature,  the  resistance  or  friction,  and  also  the  admission  into 
the  room  of  a  sufficient  quantity  of  air  to  replace  that  removed  by 
the  aspirating  shaft. 

The  suction  caused  by  a  strong  wind  blowing  across  the  top  of 
the  chimney  is  another  important  factor,  but  on  account  of  its 
uncertainty  is  seldom  taken  into  account  in  theoretical  calculations. 

To  increase  the  velocity  of  the  flow  of  air  through  an  aspirating 
chimney  or  flue  we  must  either  increase  the  height  of  the  chimney 
or  raise  the  temperature  within  the  flue. 

As  increasing  the  height  of  the  chimney  has  the  same  effect  as 
increasing  the  temperature  in  the  flue,  we  see  the  advantage  of 
having  the  chimney  as  high  as  practicable.  The  increased  height 
costs  nothing  after  the  chimney  is  built,  while  the  increase  in  heat 
is  a  constant  expense. 

In  school  buildings,  for  architectural  reasons  the  aspirating  chim- 
ney should  not  be  too  high,  consequently  we  raise  the  temperature 
of  the  air  in  the  chimney  by  means  of  heat  applied  there,  or  when 
a  mechanical  (fan)  system  of  ventilation  is  used  the  air  is  forced 
out  by  means  of  a  fan.  Air  expands  about  1/490  of  its  volume  for 
each  degree  of  increase  in  its  temperature,  and,  consequently, 
decreases  in  weight  per  cubic  foot  as  its  temperature  is  raised. 

The  heated  column  of  air  in  the  chimney,  being  lighter  than  a 
column  of  external  air  of  the  same  area  and  height,  rises,  being 
forced  up  by  the  greater  weight  of  the  external  air. 

To  find  the  theoretical  velocity  in  feet  per  second  of  air  in  a 
ventilating  chimney  : 

Let  t  =  temperature  of  the  external  air ;  t±  =  temperature  of 
the  air  within  the  chimney ;  T  =  absolute  *  temperature  of  the 
external  air;  H  =  height  of  chimney  in  feet,  and  V  =  velocity 
in  feet  per  second  ; 


Then  V  =  8.02  J  H  (/,  —  /) 

T 

By  multiplying  the  value  of  V  by  60  we  have  the  theoretical 
velocity  in  feet  per  minute. 

The  theoretical  velocity  cannot  be  obtained  in  actual  practice, 
and  a  deduction  of  from  30  to  50  per  cent  (for*  roughly  built  and 

*  Absolute  temperature  =  460  degrees  below  zero. 


THE    SCHOOL    HOUSE.  67 

crooked  flues  even  more)  should  be  made  from  the  theoretical 
velocity  for  friction  and  eddies. 

Neglect  to  make  sufficient  allowance  for  friction  in  ducts  and 

O 

aspirating  chimneys  has  been  the  cause  of  partial  failure  in  many 
an  otherwise  well-arranged  scheme  of  ventilation. 

Care  should  be  taken  that  an  aspirating  chimney  is  not  too  large 
or  too  small. 

In  the  small  chimney  the  friction  may  be  the  cause  of  failure, 
and  in  one  too  large,  eddies  will  contribute  to  the  same  result. 

By  standing  in  the  bottom  of  an  abnormally  large  aspirating 
chimney  and  throwing  into  the  different  parts  of  the  chimney 
thistle-down  or  coma  of  the  milkweed,  the  action  of  the  eddies  can 
easily  be  seen  by  watching  the  movement  of  these  light  substances. 

It  is  better  to  provide  a  separate  vent  duct  from  each  room  than 
to  enter  the  vents  from  several  rooms  into  one  large  aspirating 
chimney,  as  the  outflow  of  air  from  the  several  rooms  can  be  more 
easily  and  equally  regulated  where  separate  vent  ducts  are  provided. 

The  amount  of  heat  required  for  each  flue  and  the  position  of 
the  damper  can  then  be  regulated  to  meet  the  special  requirements 
of  each  room,  especially  when  there  is  a  strong  wind. 

At  one  time  a  very  common  method  of  heating  an  aspirating 
chimney  or  flue  was  by  placing  the  smoke-pipe  from  the  furnace  in 
the  center  of  the  chimney,  a  cast-iron  pipe  being  sometimes  used ; 
occasionally  one  made  of  drain-tile.  When  we  consider  the  low 
temperature  at  which  the  products  of  combustion  should  enter 
such  a  pipe  from  a  well-designed  furnace,  and  the  fact  that  the 
smoke-pipe  was  placed  in  the  most  effective  and  best  part  of  the 
vent  shaft,  as  well  as  the  large  increase  in  friction,  it  may  well  be 
doubted  whether  much  was  gained  by  this  process. 

Furthermore,  such  a  pipe  was  of  no  use  in  mild  weather,  when 
there  was  no  fire  in  the  furnace*  or  stove.  In  mild  weather  more 
heat  is  required  in  the  aspirating  chimney  than  when  the  outside 
temperature  is  low. 

When  several  rooms  are  vented  into  one  common  vent  shaft  there 
will' frequently  be  an  excessive  outflow  from  one  room,  while  it 
may  be  deficient  from  others. 

In  one  large  vent  shaft  there  are  more  likely  to  be  eddies  and 
counter  currents  than  where  several  smaller  vent  flues  are  used. 
When  the  ventilation  of  several  rooms  into  one  large  shaft  is 
attempted,  the  location  of  the  steam-pipes  or  radiators  will  some- 
times be  a  rather  difficult  matter  in  order  to  obtain  uniform  and 
economical  results  from  the  different  rooms. 


68  THE    SCHOOL   HOUSE. 

When,  however,  no  steam-pipes  or  radiators  are  provided  in  the 
vent  shaft  and  a  stack  heater  or  small  stove  is  installed,  as  is  the 
case  in  many  school  buildings  where  furnaces  are  used,  the  large 
common  vent  shaft  or  aspirating  chimney  becomes  a  necessity. 

In  such  cases  the  ventilation  from  the  lower  rooms  is  through 
register  openings  in  the  floor,  and  the  foul  air  is  taken  down  to  the 
bottom  of  the  basement  and  enters  the  common  shaft  below  the 
"stack  heater" 

The  air  taken  down  from  the  lower  rooms,  being  heated  by  the 
stack  heater  in  the  common  shaft,  rises,  forced  up  by  the  denser 
air  on  the  outside. 

A  damper  should  always  be  provided  in  these  ducts  leading  from 
the  first  story  rooms  to  the  bottom  of  the  common  vent  shaft. 

If  the  ventilation  from  the  second  story  rooms  enters  directly 
into  the  common  shaft  and  a  curved  damper  as  a  deflector  is  pro- 
vided at  the  vent  openings  from  the  second  story  rooms,  the  ascend- 
ing air,  in  passing  the  curved  damper  or  deflector,  will  cause  an 
induced  current  from  the  second  story  rooms  into  the  common  vent 
shaft,  on  the  same  principle  as  that  of  the  steam  siphon  often  used 
in  removing  bilge-water  from  vessels  propelled  by  steam. 

Many  tests  have  shown  that  when  this  system  is  used  the  velocity 
of  the  foul  air  from  the  second  story  rooms  is  greater  than  from  the 
first  story,  and  sometimes  it  will  be  necessary  to  use  the  damper  to 
check  the  outflow  from  the  second  story. 

The  only  advantage  in  taking  the  foul  air  from  the  first  story 
rooms  down  to  the  bottom  of  the  common  vent  shaft  is  to  have  the 
stack  heater  placed  conveniently  near  the  other  heating  apparatus, 
and  to"  avoid  the  dust  and  dirt  which  would  be  caused  by  placing 
the  stack  heater  above  the  vent  opening  directly  from  the  lower 
rooms  into  the  common  shaft. 

If  the  air  in  the  first  story  schoolrooms  is  70  degrees  F.,  and  the 
air  in  the  common  vent  shaft  has  been  raised  to  85  degrees  F.  by 
the  stack  heater  in  the  lower  part  of  the  common  shaft,  only  15 
degrees  of  heat  are  available  as  a  motive  force  in  the  shaft  at  the 
level  of  the  first  story  floor  to  overcome  the  friction  and  also  to 
cause  an  outflow  of  air  in  the  shaft  at  that  level  —  70  degrees  being 
required  to  establish  an  equilibrium  between  the  down  and  up 
ducts  at  that  level.  Above  this  level  we  have  the  advantage  of 
the  height  of  the  column  of  warm  air  between  the  first  and  second 
stories. 

The  stack  heater  should  always  be  placed  above  the  point  where 
the  down  ducts  from  the  first  story  enter  the  common  shaft. 


THE    SCHOOL    HOUSE.  69 

When  the  stack  heater  is  placed  below  this  point  a  very  large 
waste  of  fuel  takes  place,  and  satisfactory  results  will  not  be 
obtained. 

When  the  stack  heater  is  placed  opposite  the  opening  in  the  shaft 
where  the  down  duct  enters,  a  considerable  quantity  of  heat  is  radi- 
ated into  the  down  duct  and  offsets  an  equal  amount  of  heat  in  tEe 
common  shaft. 

The  air  should  pass  up  by  and  close  to  the  heated  surface  of  the 
stack  heater  to  produce  the  best  results. 

In  placing  the  stack  heater  in  the  vent  shaft  it  should  be  so  located 
that  the  air  for  the  combustion  of  the  fuel  and  the  draft  for  the 
heater  are  taken  from  outside  the  vent  shaft. 

In  some  of  the  earlier  attempts  at  ventilation  by  using  the  stack 
heater  in  the  vent  shaft,  the  heater  was  placed  entirely  within  the 
shaft  and  a  manhole  door  was  provided,  through  which  to  tend  the 
heater.  This  arrangement  did  not  give  satisfactory  results,  as  the 
supply  of  air  for  the  combustion  of  the  fuel  was  considerably  lessened 
by  the  suction  of  the  current  of  air  passing  up  all  around  the  hot 
surface  of  the  fire-pot  and  reducing  the  draft  through  the  grate,  in 
some  cases  causing  the  fire  in  the  stack  heater  to  go  out  before  the 
fuel  was  consumed. 

The  practice  of  .bringing  a  number  of  vent  ducts  together  in  one 
common  chamber  in  the  attic  of  a  schoolhouse,  and  placing  in  this 
chamber  a  quantity  of  steam-pipes,  is  not  to  be  recommended.  It 
is  much  better  and  more  economical  to  place  the  heating  surface  in 
the  separate  duct's  and  about  one  foot  above  the  top  of  the  vent 
opening  from  the  room.  In  the  first  case  we  have  only  the  lifting 
power  of  a  column  of  warm  air  from  the  level  of  the  steam-pipes 
in  the  chamber  in  the  attic  to  the  top  of  the  vent  stack,  while  in  the 
latter  case  we  have  the  lifting  power  of  the  longer  column  of  warm 
air  from  the  level  of  the  radiating  surface  just  above  the  opening 
at  the  schoolroom  floor  to  the  top  of  the  vent  stack,  or,  in  other 
words,  it  would  be  a  low  chimney  instead  of  a  high  one  we  depended 
upon  to  do  the  work. 

A  considerably  less  amount  of  heat  will  be  required  in  the  tall 
chimney  than  in  the  short  one. 

More  even  removal  of  foul  air  from  the  several  rooms  will  be 
obtained  when  using  separately  heated  vent  ducts  than  when  the 
common  chamber  in  the  attic  is  used. 

When  an  exhaust  fan  is  used,  it  is  advisable  to  bring  the  separate 
vent  ducts  into  one  common  chamber  in  the  attic  where  the  fan  is 
located,  and  to  control  the  flow  of  air  from  the  several  ducts  into 


70  THE   SCHOOL   HOUSE. 

the  common  chamber  by  a  properly  arranged  adjusting  damper  in 
each  duct. 

Theoretically,  we  can  calculate  the  amount  of  air  each  separate 
duct  should  remove,  but  in  actual  practice  the  theoretical  results 
will  seldom  be  obtained,  on  account  of  the  constantly  varying  con- 
ditions of  external  temperature  and  wind ;  consequently,  means  for 
adjusting  the  outflow  from  each  separate  duct  must  be  provided. 

In  actual  practice  20  square  feet  of  steam  radiation  surface  in  the 
vent  flue  from  an  ordinary  fifty-seat  schoolroom  (28x32x12  feet) 
placed  about  one  foot  above  the  opening  from  the  schoolroom,  will 
give  satisfactory  results  when  the  flue  is  straight  and  well  built  and 
when  the  vent  flue  has  a  cross-section  of  five  square  feet  area  (24  x 
30  inches).  If  it  becomes  necessary  for  architectural  reasons  to 
carry  a  vent  duct  nearly  horizontally  for  any  considerable  distance, 
either  under  the  floor  or  over  the  ceiling,  before  it  enters  the  per- 
pendicular flue,  this  amount  of  radiation  may  be  increased. 

Better  results  are  obtained  when  the  steam-pipes  or  radiators  are 
placed  with  the  lower  part  at  the  back  of  the  vent  flue  and  are 
inclined  up  and  toward  the  front,  than  when  an  equal  amount  of 
radiating  surface  is  placed  around  the  sides. 

The  supply  and  return  steam-pipes  for  supplying  the  vent-flue 
radiation  should  be  placed  at  the  back  of  the  flue-  If  placed  on  the 
front  side  they  will  prevent  the  dampers  being  properly  opened. 

Where  vent-flue  heaters  are  made  of  steam-pipes,  one-inch  or 
one-and-one-quarter-inch  pipes  should  be  used  and  spaced  so  that 
they  will  cover  the  whole  horizontal  distance  from  one  end  to  the 
other  of  the  vent  duct. 

Where  cast-iron  radiators  are  used  it  is  better  to  use  radiators 
which  are  thin  and  wide  and  about  45  inches  long  (5  square  feet 
per  section) ,  and  space  them  with  long  nipples  so  that  they  will 
be  evenly  distributed  across  the  full  length  of  the  duct.  Do  not 
use  extended  surface  radiators  in  a  vent  duct,  on  account  of  the 
friction  of  the  air  passing  over  the  projecting  surfaces. 

For  the  ordinary  fifty-seat  schoolroom  \2S  x  32  x  12  feet)  a  vent 
flue  24x30  inches  or  5  square  feet,  one  square  foot  to  each  ten 
persons,  has  been  found  to  be  sufficiently  large.  A  larger  flue 
than  this  is  not  required,  and  in  some  cases  has  been  found  to  be 
detrimental. 

The  opening  should  be  at  the  floor  level  and  should  be  longer 
than  it  is  high;  that  is,  the  length  should  be  30  inches  and  the 
height  24  inches.  A  curved  galvanized-iron  damper  operated  with 
a  chain  and  catch  should  be  provided  in  all  cases. 


THE    SCHOOL    HOUSE.  71 

The  proper  location  of  vent  openings  is  described  under  the  head 
of  "  circulation  of  air." 

CHIMNEYS. 

In  designing  a  heating  and  ventilating  plant  it  is  of  the  utmost 
importance  that  the  chimney  should  be  of  suitable  size  to  furnish 
a  good  draft,  as  on  the  ability  to  maintain  a  good  fire  depends  the 
successful  generation  of  heat. 

In  many  cases  an  otherwise  well-designed  plant  has  proved  a 
failure  because  the  chimney  has  not  been  of  sufficient  size  to  furnish 
suitable  draft  for  the  boilers  or  furnaces. 

The  architect  wrho  designs  the  building,  as  well  as  the  heating 
contractor,  should  see  that  the  chimney  is  properly  designed  and 
located. 

The  location  of  the  chimney  should  be  carefully  considered, 
care  being  taken  that  the  top  is  a  sufficient  distance  above  the 
highest  point  of  the  ridge,  and  that  it  is  not  placed  in  a  position 
where  the  wind  will  strike  on  towers  or  projections  and  be 
deflected  down  on  the  top  of  the  chimney  in  a  manner  that  will 
destroy  the  draft,  or,  as  in  some  cases,  cause  a  reverse  draft. 

The  writer  has  in  a  number  of  cases  been  called  upon  to  remedy 
this  defect,  which  would  not  have  occurred  had  proper  precautions 
been  taken  when  the  building  was  planned. 

Under  some  conditions  the  action  of  the  wind  against  a  tower  or 
roof  has  been  such  as  to  fill  the  boiler-room  with  gas,  which, 
escaping  through  an  open  door  in  the  boiler-room,  has  passed  up 
into  the  building  in  a  quantity  sufficient  to  make  the  rooms  above 
anything  but  comfortable  or  healthful. 

Different  writers  give  different  rules  for  the  size  of  chimneys. 

One  formula  is  :  Let  H  =  height  of  chimney,  T  =  temperature 
.of  air  entering  chimney,  /=  temperature  of  air  at  top  of  chimney, 
and  V  =  velocity  in  feet  per  second.  Then  V=  35.5  ^  H  (T — t) 

A  rule  sometimes*  used  is  to  allow  one-eighth  the  area  of  the 
grate  surface  for  area  of  chimney.  This  rule  does  not  make  any 
allowance  for  the  varying  heights  of  chimneys  and  is  of  doubtful 
utility. 

Another  rule  is :  Multiply  the  nominal  horse-power  of  the 
boiler  by  112  and  divide  the  product  by  the  square  root  of  the 
height  of  the  chimney  in  feet.  The  quotient  will  be  the  required 
area-  in  square  inches  at  top  of  chimney. 

William  J.  Baldwin  gives  as  a  rule:  "Having  the  cubic  feet 
of  air  to  pass  through  a  building  in  an  hour,  and  warmed  100°  F., 


72  THE    SCHOOL   HOUSE. 

and  requiring  the  chimney  100  feet  high,  divide  by  500,000  and 
the  answer  is  jn  square  feet  of  cross-sectional  area." 

Thomas  Hawley,  late  State  Inspector  of  Boilers  and  Examiner 
of  Engineers,  and  now  principal  of  the  "  Hawley  School  for 
Engineers,"  used  the  following  rule,  which  appears  to  be  a  safe 
one  to  follow  : 

u  Make  a  chimney  81  feet  high  and  of  an  area  equal  to  the 
collective  area  of  the  boiler  tube  openings.  If  the  chimney  is 
higher  than  this,  reduce  the  area  in  proportion  as  the  square  root 
of  the  height  exceeds  the  square  root  of  81." 

To  find  area  of  chimney,  multiply  the  collective  area  of  boiler 
tube  openings  by  9  and  divide  by  the  square  root  of  height  of 
chimney. 

These  last  two  rules  are  based  upon  the  commercial  H.P.  and 
the  evaporation  of  30  pounds  of  water  per  hour.  The  coal  to  be 
burned  is  figured  on  this  assumption,  which  is  useful  in  determin- 
ing whether  the  chimney  is  large  enough,  as  in  designing  a  new 
one,  and  may  be  used  when  either  the  area  or  the  height  is  first 
settled  upon  arbitrarily,  as  is  often  the  case  when  the  architect 
designs  a  building  with  the  chimney  a  given  height  above  the  ridge. 

For  larger  powers  the  chimney  should  be  higher  than  81  feet, 
in  which  case  the  area  can  be  less-  than  the  combined  area  of  the 
boiler  tube  openings. 

For  ordinary  schoolhouses  two  stories  high,  or  two  stories  with 
a  hall  above  the  second  story,  where  the  area  of  the  chimney  is' 
equal  to  the  combined  area  of  the  boiler  j:ube  openings,  satisfactory 
results  have  been  obtained,  and  this  may  be  considered  a  safe  rule. 

A  chimney  with  too  large  a  cross-sectional  area  may  be  the 
cause  of  poor  draft  as  well  as  one  of  too  small  area. 

The  height  of  a  chimney  is  figured  from  the  boiler  grate  to  the 
top. 

The  intensity  of  the  draft  depends  upon  the  temperature  in  the 
flue  and  the  height  of  the  chimney,  and  the  amount  of  air  moved 
is  controlled  by  the  area  of  the  chimney. 

The  amount  of  air  moved  will  vary  directly  with  the  area  of  the 
chimney  for  a  given  velocity  of  flow;  but  the  velocity  of  flow 
increases  only  as  the  square  root  of  the  height. 

Doubling  the  height  of  a  chimney  only  adds  one-half  to  its  draft 
power. 

A  square  chimney  is  of  no  more  effective  size  than  a  round 
chimney  of  equal  diameter ;  that  is,  it  is  only  equal  to  the  area  of  a 
circle  inscribed  within  the  square. 


THE    SCHOOL   HOUSE.  73 

The  friction  of  a  column  of  air  is  figured  to  take  an  area  from 
the  chimney  equal  to  the  area  all  around  two  inches  from  the  sides. 

This  should  be  considered  in  designing  a  small  high  chimney. 

Within  the  limits  of  boiler  practice  the  influence  of  temperature 
on  a  chimney  draft  is  very  small.  It  makes  but  seven  per  cent 
difference  whether  the  temperature  in  the  chimney  is  300°  or 
550°  F. 

The  space  occupied  by  a  pound  of  air  increases  rapidly  with  an 
increase  of  temperature,  and  as  the  velocity  with  which  it  moves 
out  of  the  chimney  does  not  increase  as  fast,  the  bulk  increases 
faster  than  the  ability  of  the  chimney  to  handle  it ;  consequently,  a 
temperature  is  reached  at  which  the  amount  of  air  moved  carinot 
be  increased  by  that  chimney. 

A  chimney  that  tapers  at  the  top  has  its  efficiency  decreased. 

A  cap  on  the  top  of  a  chimney  very  materially  decreases  its 
efficiency. 

A  chimney  flue  should  be  as  straight  and  as  smooth  on  the  inside 
as  practicable. 

All  connections  between  the  chimney  and  boiler  or  furnace, 
should  be  made  as  straight  and  short  as  possible. 

In  designing  a  chimney  it  should  be  remembered  :  That  the 
work  a  chimney  will  do  should  be  compared  upon  the  pounds  of 
air  it  will  handle. 

The  space  occupied  by  a  certain  weight  of  gas  increases  directly 
as  the  absolute  temperature.  The  absolute  temperature  is  460° 
added  to  the  temperature  shown  by  a  Fahrenheit  thermometer. 
The  absolute  temperature  of  the  freezing  point  is  32  +  460  =  492. 

Increasing  the  temperature  and  bulk  makes  the  air  in  the 
chimney  lighter  in  weight  and  increases  the  difference  in  the 
weight  of  the  column  inside  and  a  column  of  equal  sectional  area 
outside,  and  makes  a  higher  column  of  the  lighter  air  necessary  to 
balance  a  given  column  of  the  colder  air. 

The  difference  in  height  of  the  two  columns  gives  the  air 
velocity  due  to  this  height.  The  difference  in  the  height  of  the 
two  columns  is  the  moving  force.  Multiplying  the  difference  in 
height  of  the  two  columns  by  64.4  and  extracting  the  square  root 
will  give  the  velocity. 


CHAPTER   V. 


BOILERS. 

A  HEAT  unit  or  British  thermal  unit  (B.T.U.)  is  the 
amount  required  to  raise  the  temperature  of  one  pound 
of  water  one  degree  Fahrenheit  (from  62°  to  63°). 

A  foot  pound  is  the  unit  of  work  done,  and  is  one  pound  lifted 
one  foot. 

A  heat  unit,  B.T.U.,  is  capable  of  doing  772  foot  pounds  of 
work. 

Power  is  the  rate  at  which  an  agent  can  do  work,  and  is  the 
product  of  force,  distance  and  time. 

The  unit  of  power  is  the  horse-power  (H.P.)  and  is  the  doing 
*bf  33,000  foot  pounds  of  work  in  one  minute. 

The  commercial  horse-power  of  a  boiler,  as  adopted  by  the 
American  Society  of  Mechanical  Engineers,  is  the  evaporation  of 
30  pounds  of  water  per  hour  from  a  feed-water  temperature  of 
100°  Fahrenheit  into  steam  at  70  pounds  gauge  pressure,  which 
may  be  considered  to  be  equal  to  34 £  units  of  evaporation ;  that  is, 
equal  to  34  J  pounds  of  water  evaporated  from  a  feed- water  tempera- 
ture of  212°  Fahrenheit  into  steam  at  the  same  temperature,  and  is 
equal  to  33,305  B.T.U.  per  hour. 

Section  83  of  Chapter  102  of  the  Revised  Laws  of  Massachu- 
setts, relative  to  the  licensing  of  engineers  and  firemen,  is  as  fol- 
lows : 

"  The  horse-power  of  a  boiler  shall  be  ascertained  upon  the 
basis  of  three  horse-power  for  each  square  foot  of  grate  surface, 
for  a  power  boiler,  and  on  the  basis  of  one  and  one-half  horse- 
power for  each  square  foot  of  grate  surface,  if  the  boiler  is  used 
for  heating  purposes  exclusively.  The  engine  power  shall  be 
reckoned  upon  a  basis  of  a  mean  effective  pressure  of  forty  pounds 
per  square  inch  of  piston  for  a  simple  engine  ;  fifty  pounds  for  a 
condensing  engine  ;  and  seventy  pounds  for  a  compound  engine, 
reckoned  upon  area  of  high  pressure  piston." 

A  pound  of  coal  when  properly  burned  gives  from  13,000  to 
14,000  B.T.U.  In  actual  practice,  however,  only  40  to  50  per 
cent  of  this  is  obtainable  as  effective  in  furnaces. 


THE    SCHOOL   HOUSE.  75 

In  good  mill  practice  one  pound  of  coal,  when  well  burned,  will 
give  from  8,000  to  9,000  B.T.U.,  and  12  pounds  of  Hard  coal 
burned  per  hour  per  square  foot  of  grate  surface  is  considered 
ordinary  practice. 

In  schoolhouses  and  public  buildings  about  nine  pounds  of  hard 
coal  burned  per  hour  per  foot  of  grate  surface  may  be  considered 
the  maximum,  while  six  pounds  is  about  the  average ;  in  some 
cases  it  is  as  low  as  four  pounds. 

Different  heating  and  ventilating  engineers  vary  as  to  the  amount 
of  air  that  can  be  raised  one  degree  F.  by  one  B.T.U.,  the  amount 
ranging  from  48  to  59  cubic  feet.  A  safe  rule,  however,  is  to 
consider  one  B.T.U.  as  capable  of  raising  50  cubic  feet  of  air  one 
degree  F. 

In  designing  a  heating  and  ventilating  system  for  a  schoolhouse 
or  public  building  it  is  necessary  to  ascertain  how  much  air  is  to 
be  supplied  for  the  proper  ventilation  of  the  several  rooms  and 
corridors ;  how  much  heat  will  be  lost  from  the  building  by  con- 
duction through  exposed  surfaces,  such  as  walls  and  windows,  in 
addition  to  that  lost  by  ventilation,  and  how  much  heat  will  be 
required  to  maintain  the  desired  temperature  within  the  building ; 
in  a  steam  plant,  how  much  steam  will  be  condensed  to  maintain 
the  desired  temperature,  and  how  much  radiating  surface  will  be 
needed  to  condense  the  required  amount  of  steam ; 

How  much  coal  will  be  required  to  be  burned  to  produce  the 
necessary  amount  of  steam ; 

How  much  coal  is  to  be  burned  per  foot  of  grate  surface,  and 
how  much  heating  surface  must  be  provided  in  the  boilers  to 
generate  the  desired  amount  of  steam. 

Having  determined  the  amount  of  coal  to  be  burned  per  hour  to 
properly  heat  the  building,  the  size  of  the  boilers  can  then  be 
determined. 

The  size  of  grate  is  an  important  matter.  It  is  seldom  advis- 
able to  make  a  grate  more  than  six  feet  long.  When  longer, 
the  rear  part  is  liable  to  be  neglected,  or  the  door  left  open 
long  enough  to  produce  a  loss  of  heat  by  the  large  amount  of 
air  admitted,  and  also  possibly  causing  an  injury  to  the  fire 
sheets. 

The  grate  should  be  equal  in  width  to  the  diameter  of  the  boiler, 
and  with  its  area  made  up  as  much  as  possible  by  width  rather 
than  length. 

The  ratio  of  grate  surface  to  heating  surface  usual  in  different 
classes  of  boilers  may  be  considered  as  follows  : 


76 


THE   SCHOOL   HOUSE. 
TABLE  8. 


Type  of  Boiler. 

Grate  Surface. 

Heating  Surface. 

Horizontal  tubular,  burning  soft  coal 

1 

40  to  45 

Horizontal  tubular,  burning  hard  coal 

1 

30  to-35 

Upright  tubular,  burning  soft  coal 

1 

35 

Upright  tubular,  burning  hard  coal 

1 

30 

Water-tube,  burning  soft  coal 

1 

50  to  60 

Water-tube,  burning  hard  coal 

1 

35  to  40 

Locomotive,  burning  soft  coal 

1 

35  to  60 

In  cast-iron  boilers  it  will  vary  from  1  to  30  down  to  1  to  10, 
according  -to  the  design  of  the  boiler. 

In  schoolhouse  work,  with  horizontal  multitubular  boilers  burn- 
ing soft  coal,  1  to  35  may  be  considered  safe  practice  ;  with  hard 
coal  1  to  30. 

The  relation  that  the  size  of  the  tube  bears  to  the  grate  surface, 
and  also  the  number  of  tubes,  have  considerable  influence  upon  the 
economy  of  a  boiler.  With  different  coals  a  different  tube  opening 
is  necessary.  On  account  of  the  large  volume  of  gases  which  are 
generated  in  burning  a  pound  of  soft  coal,  a  larger  flue  area  is 
needed  to  carry  them  off  and  prevent  the  draft  being  choked. 
With  hard  coal  a  less  volume  of  gas  is  produced  and  a  smaller 
flue  area  is  required. 

The  ratio  of  the  grate  to  the  combined  area  of  the  tube  openings 
may  be  fixed  as  follows  : 

TABLE  9. 


Type  of  Boiler 

Area  of  Grate. 

Area  of  Tube 
Opening. 

Horizontal  tubular,  burning  soft  coal 

7 

1 

Horizontal  tubular,  burning  hard  coal 

9 

1 

Upright 

7 

1 

For  horizontal  tubular  boilers  up  to  48  inches  diameter  it  is 
advisable  to  use  tubes  2J  inches  diameter;  from  48  to  60  inches, 
3  inch  tubes;  from  60  to  72  inches,  3J  inch  tubes. 

When  figuring  the  heating  surface  of  a  horizontal  tubular  boiler 
the  inside  area  of  the  tubes  should  be  taken  and  not  the  outside,  as 
with  a  water-tube  boiler. 

As  upright  tubular  boilers  are  used  in  but  a  small  number  of 
school  buildings  in  Massachusetts,  their  dimensions  are  not 
given  here. 


THE    SCHOOL    HOUSE. 


77 


TABLE  10. 

TABLE  OF  STANDARD  BOILER  TUBES  FOR  HORIZONTAL  TUBULAR 

BOILERS. 


Outside  Diameter. 

Heating  Surface 
per  foot  in  length. 

Area  of                  — 
Tube  Opening.       

Inches. 

Square  Feet. 

Square  Feet. 

u 

.3273 

.0067 

14 

.3926 

.00964 

II 

.4589 

.0133 

2 

.5236 

.0179 

a 

.5890 
.6545 

.0231 
.0284 

21 

.7200 

.0349 

3 

.7853 

.0422 

H 

.8508 

.0494 

8i 

.9163 

.0580 

3| 

.9817 

..0672 

4 

1.0472 

.0759 

4d 

1.1790 

.0976 

5 

1.3680 

.1205 

That  part  of  the  shell  of  a  boiler  over  the  fire  is  the  most  effective, 
and  probably  three-eighths  of  the  heat  enters  the  boiler  there.  If 
the  fuel  burns  with  a  long  flame,  passing  the  whole  length  of  the 
boiler,  the  whole  lower  part  of  the  shell  will  receive  heat  by  radia- 
tion from  the  flame,  but  if  there  is  no  flame,  but  only  a  mass  of 
heated  gas,  then  the  shell  back  of  the  bridge  wall  is  less  efficient, 
and  only  receives  heat  by  the  contact  of  the  heated  gases. 

Some  boiler  makers  and  engineers  add  the  heating  surface  of 
both  heads  of  the  boiler.  This  gives  a  somewhat  larger  commercial 
horse-power ;  but  as  the  front  head  of  the  boiler  receives  very  little 
heat  from  the  escaping  gases,  it  is  safer  to  omit  that  head  from  the 
calculation.  If  the  rear  head  is  included  only  the  actual  heating 
surface  exposed  to  the  hot  gases  should  be  taken,  and  the  area  of 
the  tube  openings  should  be  deducted  from  the  exposed  area  of  the 
head  of  the  boiler. 

To  find  the  heating  surface  in  a  horizontal  multitubular  boiler. 
Multiply  one-half  the  circumference  of  the  boiler  in  feet  by  the 
length  of  the  shell  in  feet,  for  the  heating  surface  of  the  shell.      If 
there  is  an  overhang  deduct  it  from  the  length  of  the  boiler. 

To  find  the  area  of  heating  surface  of  tubes. 
Multiply  the  circumference  of  the  tubes   (either  inside  or   out- 
side, according  to  which  is  exposed  to  heat)  in  inches  by  length  of 


78  THE    SCHOOL    HOUSE. 

tube  in  inches,  and  reduce  the  product  to  square  feet  by  dividing 
by  144.  Multiply  the  square  feet  in  one  tube  by  the  number  of 
tubes  for  total  heating  surface  of  tubes. 

Add  together  the  square  feet  of  heating  surface  in  the  shell  of 
the  boiler  and  the  square  feet  of  heating  surface  in  the  tubes  for 
the  total  heating  surface  in  the  boiler. 

Divide  the  total  heating  surface  in  the  boiler  by  15  for  the  boiler 
maker's  commercial  horse-power  of  the  boiler. 

"    To  find  area  of  tube  surface. 

Divide  area  of  grate  by  7  or  9,  according  to  whether  hard  or 
soft  coal  is  used — 7  for  soft  and  9  for  hard  coal. 

To  find  number  of  tubes. 
Divide  collective  area  of  tubes  by  area  of  sized  tube  used. 

To  find  amount  of  heating  surface. 

Multiply  ratio  of  heating  surface  to  amount  of  grate  surface,  by 
the  amount  of  grate  surface. 

in  designing  a  boiler,  after  having  found  the  weight  of  the 
water  to  be  evaporated  per  hour  or  the  amount  of  steam  to  be 
condensed,  it  will  be  necessary  to  find  how  many  pounds  of  coal 
this  will  require  to  be  burned  per  hour. 

In  power  boilers  it  may  be  assumed  that  one  pound  of  coal  will 
evaporate  from  V»  to  10  pounds  of  water.  Dividing  the  amount  of 
water  to  be  evaporated  by  9  will  give  the  pounds  of  coal  required 
to  be  burned  per  hour. 

Dividing  the  number  of  pounds  of  coal  burned  per  hour  by  the 
number  of  pounds  of  coal  burned  per  hour ,  per  foot  of  grate 
surface,  which  may  be  assumed  as  12,  will  give  the  number  of 
square  feet  of  grate  surface,  and  from  this  the  size  of  the  boiler 
can  be  determined. 

In  ordinary  low-pressure  systems  of  heating  in  schoolhouses  it  is 
not  safe  to  figure  as  large  a  number  of  pounds  of  coal  burned  per 
hour,  or  as  small  a  grate  surface. 

When  the  plant  is  poorly  managed,  as  it  sometimes  is  by  the 
ordinary  janitor,  it  is  safer  to  estimate  the  amount  of  water  evapo- 
rated by  one  pound  of  coal  as  not  exceeding  eight  pounds,  and  the 
amount  of  hard  coal  burned  per  hour  per  foot  of  grate  surface  as  six 
pounds,  or  even  less.  On  this  basis  the  grate  area  would  be  larger. 

The  amount  of  air  space  in  a  grate  must  be  considered.  If  this 
is  too  small  a  stronger  draft  is  required  than  where  it  is  of 


THE    SCHOOL   HOUSE.  79 

sufficient  size  to  allow  the  passage  of  a  sufficient  quantity  of  air 
when  the  fire  is  packed  with  ashes  or  clinkers,  as  is  frequently  the 
case  near  the  close  of  the  school  day. 

The  material  generally  used  for  the  shells  and  heads  of  steam- 
boilers  is  the  best  quality  of  open-hearth  steel,  having  a  tensile 
strength  of  not  less  than  55,000  pounds  or  more  than  60,000  pounds" 
per  square  inch,  and  an  elongation  of  not  less  than  25  per  cent, 
nor  more  than  30  per  cent  in  a  length  of  8  inches ;  fire-box  steel 
being  used  for  shell  plates,  and  flange  steel  for  heads. 

The  tubes  should  be  of  the  best  American  manufacture  and  the 
braces  and  stay-bqlts  of  the  best  refined  iron ;  rivets  of  the  best 
quality.  As  far  as  practicable  the  man-hole  frames  should  be  of 
pressed  steel  and  the  nozzles  of  cast  steel;  the  lugs,  fronts,  bonnets, 
doors  and  other  castings  of  cast  iron  adapted  to  meet  the  require- 
ments of  the  particular  parts.  The  edges  of  shell  plates  are 
planed,  and  the  riveted  joints  for  the  most  part  are  calked  by  a 
pneumatic  calking  tool. 

The  circumference  seams  are  lapped  and  single  riveted.  For 
boilers  less  than  60  inches  in  diameter  the  longitudinal  seams  are 
lapped  and  double  riveted.  Rivet  holes  are  drilled  and  the 
riveting  done  with  a  hydraulic  riveter,  except  necessary  hand- 
riveting. 

The  drift-pin  should  be  used  as  little  as  possible. 

For  boilers  60  inches  or  more  in  diameter  the  longitudinal  seams 
are  secured  by  the  triple-riveted  butt  joint,  the  edges  of  the  plate 
being  brought  together  end  to  end,  with  a  covering  plate  above  and 
below,  and  riveted  through  the  three  sheets. 

Where  a  boiler  is  designed  for  power  or  high  pressure  it  is  much 
better  and  safer  to  use  the  triple-riveted  butt  joint  than  to  use  the 
lap  joint. 

In  return  tubular  boilers  less  than  60-  inches  in  diameter  diagonal 
braces  are  used,  one  end  of  each  being  riveted  to  the  shell  and  the 
other  bolted  to  a  tee -bar,  which  is  riveted  to  the  shell,  the  tee-bars 
being  laid  out  radially. 

When  the  diameter  is  60  inches  or  over,  through  bolts  are  used, 
running  from  head  to  head,  with  two  nuts  on  each  end,  one  inside 
and  one  outside  the  plate.  Where  the  bolts  pass  through  the  plate 
the  head  is  stiffened  by  channel-iron  bars,  one  continuous  bar  being 
used  for  each  horizontal  row  of  bolts.  Sometimes  a  combination 
of  through  bolts  and  diagonal  bracing  is  used.  The  heads  of  the 
tubes  are  beaded  over  at  both  ends  and  secured  by  a  roller  expander. 
The  holes  in  the  plate  for  the  tubes  are  drilled,  the  edges  reamed, 


80  THE    SCHOOL    HOUSE. 

and  the  corners  chamfered  off.  Where  small  pipes  are  attached  to 
the  outside  shell  the  metal  is  thickened  by  reinforcing  plates  secured 
by  rivets. 

For  main  connections  of  steam-pipes  and  safety-valve,  nozzles 
are  riveted  to  the  shell,  the  face  of  the  outer  flange  being  turned, 
and  the  flange  drilled  to  receive  the  bolts. 

The  manhole  frames  are  inside  the  opening  of  the  shell.  The 
manhole  plate  and  yoke  are  of  steel,  and  the  joint  packed  with  a 
lead  or  rubber  gasket. 

Steam  domes  are  not  commonly  used  on  Massachusetts  school- 
house  boilers,  as  with  good  construction  and  proper  management 
of  the  boilers  the  steam  is  found  to  be  quite  as  dry  without  as  with 
them.  Mud  drums  are  only  used  in  exceptional  cases. 

The  boiler  maker  should  furnish  with  each  boiler-a  cast-iron 
front  having  ash  pit  and  fire  doors  protected  by  linings,  grate  bars, 
bearers  for  grates,  wall  binders,  ash-cleaning  door  -and  frame,  arch 
bars  or  back  plates,  cast-iron  wall  plates  and  rollers  for  same, 
anchor  bolts  and  binder  bolts;  also  a  pop  safety-valve,  a  steam- 
gauge,  a  water  column  with  glass  gauge  and  gauge  cocks  and  a 
fusible  safety  plug ;  also  a  full  set  of  fire  tools  and  rack  for  the 
same.  All  boilers  should  be  subjected  to  a  hydrostatic  test  and 
examined  by  a  boiler  inspector. 

In  Massachusetts  the  use  of  a  locked  pop  safet}^-valve,  set  to 
blow  off  at  fifteen  pounds,  and  of  a  pattern  approved  by  the  Chief 
of  the  District  Police,  will  allow  a  boiler  that  is  used  exclusively 
for  heating  purposes  to  be  operated  without  employing  a  licensed 
engineer  or  fireman. 

Better  service  and  results  will  be  obtained  if  a  licensed  engineer 
or  fireman  is  employed  in  addition  to  having  the  locked  pop 
safety-valve. 

An  insurance  policy  in  some  standard  boiler  insurance  company 
for  $400  for  one  year  is  generally  furnished  by  the  boiler  maker. 

Horizontal  multitubular  return  flue  boilers  are  usually  made  for 
diameters  from  24  to  36  inches  with  T5^-inch  shell  and  |-inch  heads  ; 
for  54-inch  diameters  ^-inch  shell  and  |-inch  heads.  These  are 
for  100  pounds  working  pressure  per  square  inch. 

For  60-inches  diameter,  boilers  generally  have  |-inch  shell  and 
^-inch  heads,  and  for  66  to  72-inches  diameter  T7R-inch  shell  and 
^-inch  heads,  for  a  working  pressure  of  125  pounds  per  square 
inch. 

The  following  table  is  from  the  Hodge  Boiler  Works,  East 
Boston,  Mass. 


THE    SCHOOL   HOUSE. 


81 


TABLE    11. 

STANDARD  SIZES  OF  HORIZONTAL  RETURN  TUBULAR  BOILERS. 
(Externally  Fired.) 


Diam. 
of 
Shell. 

length 
of 
Shell. 

Number 
of 
Tubes. 

Outside 
Diam- 
eter of 
Tubes 

Length 
of 
Tubes. 

Area 
through 
Tubes. 

Thick- 
ness of 
Shell. 

Thick- 
ness  of 
Heads. 

Heating 
Surface. 

Rated 
Horse- 
Pdwer. 

Approxi- 
mate 
Weight  of 
Boilers. 

Approxi- 
mate Weight 
of  Castings 
and 
Fixtures. 

Total 

Weight. 

In. 

Ft.     In. 

In. 

Ft. 

Sq.  Ft. 

In. 

In. 

Sq.  Ft. 

H.P. 

Lbs. 

Lbs. 

Lbs. 

24 

5    8 

26 

2 

5 

.43 

i 

4 

3 

8 

80 

5 

1,040 

920 

1,960 

24 

6    8 

26 

2 

6 

.43 

JL 
4 

95 

6 

1,165 

920 

2,085 

24 

7    8 

26 

2 

7 

.43 

I 

| 

110 

7 

1,290 

920 

2,210 

24 

8    8 

26 

2 

8 

.43 

i 

| 

125 

8 

1  ,450 

920 

2,370 

24 

9    8 

26 

2 

9 

.43 

L 
4 

1 

140 

9 

1,575 

920 

2,495 

30 

6    9 

36 

2 

6 

.60 

i 

| 

129 

9 

1,550 

1,400 

2,950 

30 

7    9 

36 

2 

7 

.60 

1 

4 

| 

150 

10 

1,750 

1,475 

3,225 

30 

89       36 

2 

8 

.60 

i 

3- 

170 

11 

1  ,950 

1,475 

3,425 

30 

9    9       36 

2 

9 

.60 

1 
4 

i 

191 

13 

2,100 

1,475 

3,575 

30 

10    9 

36 

2 

10 

.60 

1 

4 

| 

211 

14 

2,250 

1,530 

3,780 

30 

11    9 

36 

2 

11 

.60 

1 
4 

D 

232 

15 

2,400 

1,630 

4,030 

30 

12    9 

36 

2 

12 

.60 

i 

1 

252 

17 

2,600 

1,800 

4,400 

36 

8    3 

34 

24 

7 

.94 

1 

| 

183 

12 

2,160 

2,025 

4,185 

36 

9    3 

34 

24 

8 

.94 

i' 

| 

208 

14 

2,400 

2,025 

4,425 

36 

10    3 

34 

«i 

9 

.94 

4 

1 

233 

16 

2,550 

2,100 

4,650 

36 

11    3 

28 

3 

10 

1.15 

1 

i 

222 

15 

2,750 

2,250 

5,000 

36 

12    3 

28 

3 

11 

1.15 

4 

& 

243 

16 

2,900 

2,250 

5,150 

36 

13    3 

28 

3 

12 

1.15 

1 
4 

I 

264 

18 

3,200 

2,450 

5,650 

42 

10    3 

38 

3 

9 

1.57 

A 

| 

309 

21 

3,600 

2,500 

6,100 

42 

11    3 

38 

3 

10 

1.57 

* 

341 

23 

4,050 

2,500 

6.550 

42 

12    3 

38 

3 

11 

1.57 

A 

1 

374 

25 

4,260 

2,725 

6,985 

42 

13    3 

38 

3 

12 

1.57 

A 

1 

407 

27 

4,525 

2,725 

7,250 

42 

14    3 

38 

3 

13 

1.57 

A 

i 

440 

29 

4,850 

2,725 

7,575 

42 

15    3 

38 

3 

14 

1.57 

ft 

i 

473 

32 

5,200 

2,725 

7,925 

42 

16    3 

38 

3 

15 

1.57 

A 

1 

506 

34 

5,450 

3,000 

8,450 

48 

11    3 

49 

3 

10 

2.02 

A 

t 

432 

29 

5,150 

3,250 

8,400 

48 

12    3 

49 

3 

11 

2.02 

ft 

3 

474 

32 

5.550 

3,360 

8,910 

48 

13    3 

49 

3 

12 

2.02 

A 

| 

515 

34 

6,000 

3,360 

9,360 

48 

14    3 

49 

3 

13 

2.02 

A 

| 

557 

37 

6,300 

3,360 

9,660 

48 

15    3 

49 

3 

14 

2.02 

A 

3. 

599 

40 

6,600 

3,750 

10,350 

48 

15    3 

41 

34 

14 

2.36 

A 

I 

593 

40 

6,750 

3,750 

10.500 

48 

16    3  i     49 

3 

15 

2.02 

ft 

2. 

640 

43 

7,000 

3,900 

10,900 

48 

16    3 

41 

34 

15 

2.36 

A 

1 

633 

42 

7,150 

3,900 

11,050 

48 

16    3 

30 

4 

15 

2.3 

A 

| 

552 

37 

7,000 

3,900 

10,900 

48 

17    3 

49 

3 

16 

2.02 

A 

e 

682 

45 

7,400 

3,900 

11,300 

48 

17    3 

41 

34 

16 

2.36 

A 

| 

668 

45 

7,500 

3,900 

11,400 

48 

17    3 

30 

4 

16 

2.3 

S 

3- 

8 

590 

39 

7,400 

3,900 

11,300 

54 

15    3 

60 

3 

14 

2  47 

Ii 

a 

725 

48 

7.800 

4,200 

12,000 

54 

15    3 

49 

8* 

14 

2.82 

1 

i 

703 

47 

7,900 

4,200 

12,100 

54 

15    3 

42 

4 

14 

3.22 

a 

696 

46 

8,250 

4,200 

12,450 

54 

16    3 

60 

3 

15 

2.47 

1 

116 

52 

8,200 

4,400 

12,600 

54 

16    3 

49 

34 

15 

2.82 

1 

752 

50 

8,300 

4,400 

12,700 

54 

16    3 

42 

4 

15 

3  22 

I 

745 

50 

8,700 

4,400 

13,100 

54 

17    3 

80 

3 

16 

2.47 

1 

826 

55 

8,650 

4,400 

13,050 

82 


THE    SCHOOL   HOUSE. 
TABLE    11.  —  Continued 


Diam. 
of 
Shell. 

Length 
of 
Shell. 

Number 
of 
Tubes. 

Outside 
Diam- 
eter of 
Tubes. 

Length 
of 
Tubes. 

Area 
through 
Tubes. 

Thick- 
ness of 
Shell. 

Thick- 
ness of 
Heads. 

Heating 
Surface. 

Rated 
Horse- 
Power. 

Approxi- 
mate 
Weight  of 
Boilers. 

Approxi- 
mate Weight 
of  Castings 
and 
Fixtures. 

Total 
Weight 

In. 

Ft.     In. 

In. 

Fr. 

Sq.  Ft. 

In. 

In. 

Sq.  Ft. 

H.P. 

Lbs. 

Lbs. 

Lbs. 

54 

17    3 

49 

Si 

16 

2.82 

H 

a 

801 

53 

8,900 

4,400 

13,200 

54 

17    3 

42 

4 

16 

3.22 

1  1 

| 

793 

53 

9,150 

4,400 

13,550 

54 

18    3 

60 

3 

17 

2.47 

T[ 

•| 

876 

58 

9,100 

4,400 

13,500 

54 

18    3 

49 

34 

17 

2.82 

ii 

| 

850 

57 

9,200 

4,400 

13,600 

54 

18    3 

42 

4 

17 

3.22 

32 

8 

841 

56 

9,600 

4,400 

14,000 

60 

15    3 

80 

3 

14 

3.3 

| 

i 

942 

63 

10,450 

5,150 

15,500 

60 

15    3 

64 

34 

14 

3  69 

| 

- 

;. 

898 

60 

10,650 

5,150 

15,800 

60 

15    3 

58 

4 

14 

4.45 

2 

931 

62 

11,350 

5,150 

16,500 

60 

16    3 

80 

3 

15 

3.3 

.| 

1,008 

67 

11,050 

5,150 

16,200 

60 

16    3 

64 

34 

15 

3.69 

| 

960 

64 

11,250 

5,150 

16,400 

60 

16    3 

58 

4 

15 

4.45 

| 

996 

66 

11,950 

5,150 

17,100 

60 

17    3 

80 

3 

16 

3.3 

f 

| 

1,073 

72 

11,800 

5,150 

16,950 

60 

17    3 

64 

34 

16 

3.69 

1 

1,022 

68 

12,000 

5,150 

17,150 

60 

17    3 

58 

4 

16 

4.45 

i 

1 

1,061 

71 

12,700 

5,150 

17,850 

60 

18    3 

80 

3 

17 

3.3 

| 

I 

1,139 

76 

12,560 

5,150 

17,710 

60 

18    3 

64 

34 

17 

3.69 

| 

1,085 

72 

12,780 

5,150    ^ 

*!7,930 

60 

18    3 

58 

4 

17 

4.45 

f 

1 

1,125 

75 

13,450 

5,150 

18,600 

66 

16    4 

110 

3 

15 

4.54 

ft 

| 

1,348 

90 

14,600 

5,400 

20,000 

66 

16    4 

79 

34 

15 

4.55 

ft 

I 

1,168 

78 

14,600 

5,400 

20,000 

66 

16    4 

62 

4 

15 

4.76 

ft 

1,073 

72 

14,600 

•5,400 

20,000 

66 

17    4 

110 

3 

16 

4.54 

ft 

1,436 

96 

15,500 

5,400 

20,900 

66 

17    4 

79 

34 

16 

4.55 

ft 

1,244 

83 

15,400 

5,400 

20,800 

66 

17    4 

62 

4 

16 

4.76 

ft 

1,142 

76 

15.600 

5,400 

20,900 

66 

18    4 

110 

3 

17 

4.54 

ft 

1,524 

102 

16,300 

5,400 

21,700 

66 

18    4 

79 

34 

17 

4.55 

ft 

1 

1,320 

88 

16,200 

5,400 

20,600 

66 

18    4 

62 

4 

17 

4.76 

ft 

if 

1,212 

81 

16,300 

5,400 

21,700 

72 

16    4 

140 

3 

15 

5.77 

ft 

1.689 

113 

16,100 

5,650 

21,750 

72 

16    4 

92 

34 

15 

5.3 

1,352 

90 

16,375 

5,650 

22,025 

72 

16    4 

76 

4 

15 

5  83 

1,296 

86 

16,270 

5,650 

21,920 

72 

17    4 

140 

3 

16 

5.77 

1,799 

120 

16,725 

5,650 

22,375 

72 

17    4 

92 

34 

16 

5.3 

ft 

1,440 

96 

17,000 

5,650 

22.650 

72 

17    4 

76 

4 

16 

5.83 

ft 

1.380 

92 

16,895 

5,650 

22,545 

72 

18    4 

140 

3 

17 

5.77 

_L. 

1,909 

128 

17,450 

5,650 

23,100 

72 

18    4 

92 

34 

17 

53 

Jg- 

1,528 

102 

17,725 

5,650 

23,375 

72 

18    4 

76 

4 

17 

5  83 

ft 

- 

1,464 

98 

17,620 

5,650 

23,270 

72 

19    4 

92 

34 

18 

5  3 

JL 

1 

1,615 

108 

18,750 

5,650 

24,400 

72 

20    4 

92 

34 

19 

5.3 

~is 

1 

1,703 

103 

19,680 

5,650 

25,330 

72 

21    4 

92 

34 

20 

5.3 

2 

* 

1,790 

119 

20,580 

5,650 

26,234 

These  horizontal  return  tubular  boilers  have  the  same  dimen- 
sions, whether  they  are  set  with  overhanging  fronts  or  flush  fronts, 
and  the  table  may  be  used  indiscriminately  for  either. 

The  heating  surface  given  in  the  table  is  the  area  which  is 
directly  exposed  to  the  heat  of  the  products  of  combustion;  that  is, 


THE   SCHOOL   HOUSE.  83 

the  exterior  surface,  in  the  case  of  the  shell  and  heads,  and  the 
interior  surface  in  the  case  of  the  tubes. 

The  rated  horse-power  given  is  based  upon  15  square  feet  of 
heating  surface  per  horse-power. 

With  the  draft  of  a  good  chimney  80  feet  high  and  proper  jlue 
connections,  the  rated  capacity  can  easily  be  produced  under  work- 
ing conditions  with  good  coal,  it  being  understood  that  a  horse- 
power refers  to  the  evaporation  of  34J  pounds  of  water  per  hour 
from  and  at  212°  F.  (A.S.M.E.  standard). 

Beyond  the  rating  stated  there  is  a  surplus  capacity  of  at  least 
one-third  when  the  full  draft  of  the  chimney  is  on  and  the  fire  is 
urged. 

With  high  chimneys  and  the  best  grade  of  bituminous  coal  the 
boilers  can  be  worked  to  much  higher  capacities  than  those  noted 
in  the  table. 

The  thickness  of  boiler  plates  within  ordinary  use  makes  but 
little  difference  in  the  ability  of  the  plate  to  conduct  heat. 

A  coating  or  incrustation  on  the  plates  and  tubes  makes  consid- 
erable difference  in  the  efficiency  and  life  of  a  boiler  and  should  be 
carefully  guarded  against.  This  is  a  matter  that  is  often  badly 
neglected  by  janitors  in  school  buildings. 

The  setting  of  a  boiler  is  a  matter  to  be  carefully  attended  to  in 
order  that  cracks  may  not  appear  and  allow  air  to  enter  and  cool 
the  temperature  of  the  fire  and  gases  in  the  furnace. 

In  setting  a  boiler  on  marshy  or  filled  ground  especial  care 
should  be  taken  to  secure  a  good  foundation,  and  in  some  cases  a 
thick  foundation  of  good  concrete  should  be  put  under  the  whole 
apparatus  to  prevent  unequal  settling  and  cracking  of  the  walls. 

Before  a  boiler  is  set  the  nature  of  the  ground  should  be  carefully 
investigated. 

In  setting  the  fire-brick  in  a  furnace  they  should  be  laid  with  but 
a  small  quantity  of  fire-clay  between  them,  but  sufficient  to  level 
the  work. 


84 


THE    SCHOOL   HOUSE. 


TABLE  12. 

(Hodge  Boiler   Works,  East  Boston,  Mass.} 

DIMENSIONS  RELATING  TO  BRICK  SETTING  FOR  HORIZON- 
TAL RETURN  TUBULAR  BOILERS;  NUMBER  OF  BRICKS 
GIVEN  BEING  APPROXIMATE. 


Ft.     In.      Ft.     In. 

Ft.     In. 

Ft.     In. 

Ft.     In. 

Ft.     In. 

Diameter  of  shell 

42 

48 

54 

60 

66 

72 

Length  of  shell  over  all 

13      3 

15      3 

16      3 

16      3 

17      4 

17      4 

Length    of   brick    setting 

over  all  with  overhang- 

ing fronts 

15      3 

17      6 

18      6 

18      6 

19      7 

19      7 

Length    of   brick    setting 

over  all  with  flush  fronts 

16      6 

18      9 

19      9 

19      9 

20    10 

20    10 

Width  of  brick  setting  for 

single  boiler 

7      7 

8      1 

8      7 

9      1 

9      7 

10      1 

Increase  in  width  of  set- 

ting for  each  additional 

boiler  in  a  battery 

5    11 

6      5 

6    11 

7      5 

7    11 

8      5 

Length  of  grate 

3      6 

4      0 

4      6 

5      0 

5      6 

6      0 

Width  of  grate 

3      6 

4      0 

4      6 

5      0 

5      6 

6      0 

Vertical     distance     from 

floor  to  shell 

3      9 

3      9 

4      0 

4      0 

4      0 

4      0 

Vertical      distance     from 

grate  to  shell  at  front 

end 

22 

22 

24 

24 

24 

24 

Vertical      distance     from 

floor    to    top    of    brick 

work 

7      7 

8      1 

8    10 

9        4 

9    10 

10      4 

Number  of  red  brick  re- 

quired for  setting  single 

' 

boiler        overhanging 

front 

11,923 

14,563 

16,819 

17,977 

20,048 

21,359 

Flush  front 

12,860 

15,568 

17,903 

19,110 

21,245 

22,624 

Number  of  fire  brick  re- 

quired for  a  single  boiler 

765 

884 

1,059 

1,179 

1,359 

1,526 

Number  of  red  brick  re- 

quired   for   each    addi- 

tional boiler  of  a  battery 
overhanging  front 

7,757 

9,550 

11,022 

12,065 

13,361 

14,323 

Flush  front 

8,335 

10,174 

11,695 

12,773 

14,109 

15,116 

Number  of  fire  brick  for 

each    additional    boiler 

of  a  battery 

765 

884 

1,059 

1,179 

1,359 

1,526 

Number  of  red  brick  re- 

quired   for    each    addi- 

.**' 

tional  length  of  one  foot 

in  the  length  of  a  single 
boiler 

703 

754 

813 

850 

898 

949 

Number  of  red  brick  re- 

quired   for  each    addi- 

tional length  of  one  foot 

in   the   length  of   each 

additional  boiler 

434 

468 

-505 

531 

561 

595 

NOTE.  —  When  the  thickness  of  the  inside  walls  is  8  inches,  instead  of  12  inches,  to  which  the 
above  table  applies,  the  number  of  red  brick  required  for  the  various  sizes  of  boilers  given  is  as 
follows : 


THE    SCHOOL    HOUSE. 
TABLE  13. 


85 


Single  boiler,  overhang-  \ 
ing  front.                         / 

10,146 

12,534 

14,429 

15,327 

17,392 

18,585 

Single  boiler,  flush  front 

10,962 

13,412 

15,383 

16,331 

18,458 

19,713 

Each  additional  boiler,  \ 
overhanging  front        J 

5,751 

7,189 

8,315 

8,879 

10,238 

11,084 

Each  additional  boiler,  \ 
flush  front                       / 

6,281 

7,759 

8,925 

9,529 

10,928 

11,814 

SMOKE  FLUES  FOR  STEAM-BOILERS. 

The  smoke  flues  connecting  steam-boilers  to  the  chimney  should 
be  constructed  of  iron ;  brick  ones  do  not  prove  satisfactory. 

In  most  smoke-flue  work  No.  12  tank  iron  is  used  unless  other- 
wise specified. 

The  two  kinds  generally  used  are  those  of  circular  cross-section 
and  those  of  a  rectangular  shape. 

The  seams  of  circular  flues  are  lap  riveted,  and  the  rectangular 
ones  are  joined  together  at  the  corners  by  angle  irons,  and  where 
the  flue  is  of  considerable  width  it  is  stiffened  by  the  same  means. 
The  short  branch  flue  which  connects  immediately  to  the  boiler 
(the  uptake  in  a  horizontal  boiler)  is  provided  with  a  damper. 
The  main  flue  between  the  last  boiler  and  the  chimney  is  fitted 
with  a  regulating  damper  for  controlling  the  entire  battery  of 
boilers.  The  size  of  the  flue  should  be  equal  to  the  collective  area 
of  the  tube  openings  in  all  the  boilers  to  which  it  is  connected.  A 
clean-out  which  can  be  closed  air-tight  should  be  provided. 

Flues  should  be  as  short  and  straight  as  practicable,  and  where 
a  change  of  direction  is  made  it  should  be  by  a  curve  rather  than  a 
sharp  or  square  angle. 

RULES  FOR  DETERMINING   PRESSURE  A  BOILER  WILL   SUSTAIN  : 

United  States    Government  Standard. 

Divide  tensile  strength  of  metal  by  6  and  multiply  by  thickness 
of  stock.  Divide  product  by  radius  of  boiler  in  inches.  The 
quotient  is  the  steam  pressure  the  boiler  will  sustain. 

Massachusetts  Inspectors'   Rule. 

Multiply  the  thickness  of  sheet  by  tensile  strength.  Multiply 
this  product  by  56  per  cent  if  single  riveted,  or  by  70  per  cent  if 
double  riveted;  by  80  or  85  per  cent  if  butt-strap  riveted.  The 
quotient  is  the  bursting  pressure.  For  safe  pressure  divide  burst- 
ing pressure  by  4£  or  5,  according  to  the  condition  of  the  boiler. 


86  THE   SCHOOL   HOUSE. 

WATER-TUBE  BOILERS. 

Water-tube  boilers  are  boilers  in  which  the  water  is  inside  the 
tubes  and  the  heat  is  applied  from  the  outside,  instead  of  having 
the  water  on  the  outside  and  the  heat  inside  the  tubes,  as  in  hori- 
zontal or  upright  boilers. 

This  class  of  boilers  is  used  to  a  limited  extent  in  schoolhouses 
in  Massachusetts ;  generally  where  a  mechanical  (fan)  system  of 
heating  and  ventilation  has  been  installed,  or  where  the  architect 
has  not  provided  a  boiler-room  of  sufficient  size. 

They  generate  steam  quickly  and  can  be  forced  when  under  the 
charge  of  a  skilful  engineer,  and  have  given  good  results,  especially 
where  a  fan  is  used  ;  but  for  ordinary  small  or  moderate  size  school- 
houses  the  return  tubular  class  is  to  be  preferred. 

UPRIGHT  TUBULAR  BOILERS. 

Upright  tubular  boilers  have  been  used  in  schoolhouses ;  but  to 
a  limited  extent  and  where  it  has  been  desired  to  run  an  engine  at 
high  pressure  to  drive  a  fan  or  blower. 

They  occupy  but  little  floor  space,  but  in  the  ordinary  school- 
house  basement  require  that  a  pit  be  provided  to  keep  the  top  of 
the  boiler  sufficiently  below  the  ceiling. 

It  is  generally  better  to  use  a  low-pressure  engine  having  a 
cylinder  of  large  diameter  and  short  stroke,  rather  than  to  install  a 
high-pressure  engine  driven  t}y  steam  at  high  pressure  from  an 
upright  boiler. 

CAST-IRON  SECTIONAL  BOILERS. 

Cast-iron  sectional  boilers  have  been  used  to  a  considerable  extent 
in  schoolhouses,  but  the  results  obtained  are  not  in  the  majority  of 
cases  as  satisfactory  as  when  the  return  horizontal  tubular  class 
are  used. 

There  are  many  different  patterns :  good,  indifferent  and  bad. 
Different  manufacturers  claim  their  design  to  be  the  best,  and  to 
describe  them  all  would  be  beyond  the  scope  of  this  book. 

In  many  cases  a  higher  rating  for  efficiency  is  given  in  catalogues 
than  is  shown  in  the  actual  work  performed.  If  the  designer  of 
the  heating  system  in  a  schoolhouse  depends  upon  the  catalogue 
rating  of  many  of  this  class  of  boilers,  he  will  be  sadly  disappointed 
in  the  final  test. 

A  large  factor  of  safety  should  be  allowed  for  rating  many  of 
this  class  of  boilers.  In  installing  them  in  schoolhouses  it  is  well 
to  obtain  from  the  manufacturer  a  good  and  sufficient  guarantee 
that  the  boiler  will  do  the  work  required. 


THE    SCHOOL    HOUSE.  87 

Many  of  this  class  have  a  large  amount  of  heating  surface  and 
a  small  amount  of  water  and  steam  space,  and  when  forced  the 
water  is  carried  into  the  heating  coils  or  radiators  and  trouble  is 
caused  by  low  water  in  the  boiler,  melting  out  the  fusible  plug  and 
cracking  sections  of  the  boiler. 

The  writer  has  seen  many  cases  where  this  has  occurred  and 
caused  the  shutting  down  of  the  heating  apparatus.  This  has 
been  particularly  noticeable  in  the  small  cast-iron  sectional  boilers 
so  generally  used  for  heating  the  vent  shafts  and  for  supplying 
direct  radiation  in  corridors,  teachers'  rooms,  etc.,  in  school- 
houses. 

Where  this  class  of  boilers  is  used  care  should  be  taken  to  select 
a  boiler  of  ample  size  to  do  the  work  required,  and  one  that  has 
a  proper  proportion  of  heating  surface  to  the  water  and  steam 
space ;  also  one  that  does  not  have  a  large,  flat,  unstayed  heating 
surface. 

REQUIREMENTS  OF  BOILER  INSPECTION  DEPARTMENT  OF 
MASSACHUSETTS  DISTRICT  POLICE  AS  TO  FITTINGS  FOR 
LOW-PRESSURE  HEATING  BOILERS. 

Upon  all  steam  boilers  used  for  heating  purposes,  having  a  grate  area  of 
over  two  square  feet,  and  subject  to  inspection  by  this  department,  the  fol- 
lowing fittings  must  be  provided,  being  deemed  necessary  for  safety. 

One  safety-valve  on  each  boiler  with  no  obstruction  between  valve  and 
boiler.  If  pressure  carried  is  to  be  below  25  pounds,  the  least  area  of  the 
safety-valve  in  inches  is  to  be  reckoned  by  dividing  the  area  of  grate  in 
square  feet  by  2&  if  a  pop  valve  is  used,  or, by  two  if  a  lever,  dead-weight,  or 
simple  spring  valve  is  used. 

One  steam  gauge  on  each  boiler,  connected  with  syphon  or  equivalent 
device  between  gauge  and  boiler,  to  fill  gauge  spring  with  water.  The  supply 
pipe  is  to  come  from  steam  space  of  boiler. 

Each  boiler  must  have  at  least  two  try-clocks,  the  lower  one  to  be  placed 
2^  inches  above  fusible  plug  or  lowest  safe  water  line.  Where  a  glass  is  also 
used  the  lower  end  of  glass  must  be  above  the  fusible  plug  or  lowest  safe 
water  line. 

Each  boiler  must  be  provided  with  stop  valve  on  main  steam  pipe  leading 
from  boiler.  Each  boiler  must  have  check  valve  and  stop  valve  on  main 
return  pipe. 

Where  a  damper  regulator  is  used,  the  pressure  supply  pipe  must  be  taken 
from  the  steam  space  of  the  boiler,  with  proper  water  syphon. 

SAFETY-VALVES   FOR    HIGH    PRESSURE. 

If  pressure  carried  is  between  25  and  100  pounds,  the  area  of  safety-valve 
in  inches  shall  equal  the  area  of  grate  in  square  feet  divided  by  3,  for  lever  or 
dead-weight  valves,  and  by  3i  for  pop  valves  If  pressure  is  above  100  pounds, 
divide  by  5  for  pop  valves  and  by  4  for  lever  or  dead-weight  valves. 


88  THE    SCHOOL    HOUSE. 

SECTIONS  78  TO  86  INCLUSIVE  OF  CHAPTER  102  OF  THE 
REVISED  LAWS  OF  MASSACHUSETTS,  RELATIVE  TO  THE 
LICENSING  OF  ENGINEERS  AND  FIREMEN. 

As  AMENDED  BY  CHAPTER  310,  ACTS  OF  1905. 

SECTION  78.  No  person  shall  have  charge  of  or  operate  a  steam  boiler  or 
engine  in  this  Commonwealth,  except  boilers  and  engines  upon  locomotives, 
motor  road  vehicles,  boilers  in  private  residences,  boilers  in  apartment 
houses  of  less  than  five  flats,  boilers  under  the  jurisdiction  of  the  United 
States,  boilers  used  for  agricultural  purposes  exclusively,  boilers  of  less  than 
eight  horse  power,  and  boilers  used  for  heating  purposes  exclusively  which 
are  provided  with  a  device  approved  by  the  chief  of  the  district  police 
limiting  the  pressure  carried  to  fifteen  pounds  to  the  square  inch,  unless  he 
holds  a  license  as  hereinafter  provided.  The  owner  or  user  of  a  steam 
boiler  or  engine,  other  than  boilers  or  engines  above  excepted,  shall  not 
operate  or  cause  to  be  operated  a  steam  boiler  or  engine  for  a  period  of  more 
than  one  week,  unless  the  person  in  charge  of  and  operating  it  is  duly 
licensed. 

SECTION  79.  If  such  steam  engine  or  boiler  is  found  to  be  in  charge  of 
or  operated  by  a  person  who  is  not  a  duly  licensed  engineer  or  fireman  and, 
after  a  lapse  of  one  week  from  such  time,  it  is  again  found  to  be  operated  by 
a  person  who  is  not  duly  licensed,  it  shall  be  deemed  prima  facie  evidence 
of  a  violation  of  the  provisions  of  the  preceding  section. 

SECTION  80.  The  words  "have  charge"  or  "in  charge,"  in  the  two 
preceding  sections,  shall  designate  the  person  under  whose  supervision  a 
boiler  or  engine  is  operated.  The  person  operating  shall  be  understood  to 
mean  any  and  all  persons  who  are  actually  engaged  in  generating  steam  in  a 
power  boiler. 

SECTION  81.  Whoever  desires  to  act  as  engineer  or  fireman  shall  apply 
for  a  license  therefor  to  the  examiner  of  engineers  for  the  city  or  town  in 
which  he  resides  or  is  employed,  upon  blanks  to  be  furnished  by  the 
examiner.  The  application  shall  be  accompanied  by  a  fee  of  one  dollar  and 
shall  show  his  total  experience.  Wilful  falsification  in  the  matter  of  state- 
ments contained  in  the  application  shall  be  deemed  sufficient  cause  for  the 
revocation  of  said  license  at  any  time.  The  applicant  shall  be  given  a 
practical  examination  and,  if  found  competent  and  trustworthy,  he  shall 
receive,  within  six  days  after  the  examination,  a  license  gradeds  according  to 
the  merits  of  his  examination,  irrespective  of  the  grade  of  license  for  which 
he  applies.  The  applicant  shall  have  the  privilege  of  having  one  person 
present  during  his  examination,  who  shall  take  no  part  in  the  same,  but  who 
may  take  notes  if  he  so  desires.  No  person  shall  be  entitled  to  receive  more 
than  one  examination  within  ninety  days,  except  in  the  case  of  an  appeal  as 
hereinafter  provided.  A  license  shall  continue  in  force  for  three  years,  or 
until  it  is  revoked  for  the  incompetence  or  untrustworthiness  of  the  licensee  ; 
and  a  license  shall  remain  revoked  until  a  new  license  is  granted.  A  license, 
unless  revoked,  shall  be  renewed  by  an  examiner  of  engineers  upon 
application  and  without  examination,  if  the  application  for  renewal  is  made 
within  six  months  after  its  expiration.  If  a  new  license  of  a  different  grade 
is  issued,  the  old  license  shall  be  destroyed  in  the  presence  of  the  examiner. 
If  a  license  is  lost  by  fire  or  other  means,  a  new  license  shall  be  issued  in  its 


THE    SCHOOL   HOUSE.  89 

place,  without  re-examination  of  the  licensee,  upon  satisfactory  proof  of  such 
loss  to  an  examiner. 

SECTION  82.  Licenses  shall  be  granted  according  to  the  competence  of 
the  applicant,  and  shall  be  distributed  in  the  following  classes  :  Engineers' 
licenses:  —  First  class,  to  have  charge  of  and  operate  any  steam  plant. 
Second  class,  to  have  charge  of  and  operate  a  boiler  or  boilers,  and  to  have 
charge  of  and  operate  engines,  no  one  of  which  shall  exceed  one  hundred 
and  fifty  horse  power,  or  to  operate  a  first-class  plant  under  the  engineer  in 
direct  charge  of  the  plant.  Third  class,  to  have  charge  of  and  operate  a 
boiler  or  boilers  not  exceeding  in  the  aggregate  one  hundred  and  fifty  horse- 
power, and  an  engine  not  exceeding  fifty  horse-power,  or  to  operate  a 
second-class  plant  under  the  engineer  in  direct  charge  of  the  plant  Fourth 
class,  to  have  charge  of  and  operate  hoisting  and  portable  engines  and 
boilers.  Firemen's  licenses:  —  Extra  first  class,  to  have  charge  of  and 
operate  any  boiler  or  boilers.  First  class,  to  operate  any  boiler  or  boilers. 
Second  class,  to  have  charge  of  and  operate  any  boiler  or  boilers  where  the 
pressure  carried  does  not  exceed  twenty-five  pounds  to  the  square  inch,  or 
to  operate  high  pressure  boilers  under  the  engineer  or  fireman  in  direct 
charge  thereof.  A  person  holding  an  extra-first  or  first-class  fireman's 
license  may  operate  a  third-class  plant  under  the  engineer  in  direct  charge  of 
the  plant  A  person  who  desires  to  have  charge  of  or  to  operate  a  particular 
steam  plant  or  type  of  plant  may,  if  he  files  with  his  application  a  written 
request  signed  by  the  owner  or  user  of  said  plant  for  such  examination,  be 
examined  as  to  his  competence  for  such  service  and  no  other,  and  if  found 
competent  and  trustworthy  shall  be  granted  a'  license  for  such  service  and 
no  other. 

SECTION  83.  The  horse-power  of  a  boiler  shall  be  ascertained  upon  the 
basis  of  three  horse-power  for  each  square  foot  of  grate  surface,  for  a  power 
boiler,  and  on  the  basis  of  one  and  one-half  horse-power  for  each  square  foot 
of  grate  surface,  if  the  boiler  is  used  for  heating  purposes  exclusively.  The 
engine  power  shall  be  reckoned  upon  a  basis  of  a  mean  effective  pressure  of 
forty  pounds  per  square  inch  of  piston  for  a  simple  engine ;  fifty  pounds  for 
a  condensing  engine;  and  seventy  pounds  for  a  compound  engine,  reckoned 
upon  area  of  high-pressure  piston. 

SECTION  84.  A  person  who  is  aggrieved  with  the  action  of  an  examiner 
in  refusing  or  revoking  a  license  may,  within  one  month  after  his  decision, 
appeal  therefrom  to  the  remaining  examiners,  who  shall  together  act  as  a 
board  of  appeal,  and  a  majority  of  whom  shall  have  the  power  to  hear  the 
parties  and  pass  upon  the  subjects  of  appeal.  The  applicant  may  have  the 
privilege  of  having  one  first-class  engineer  present  during  the  hearing  of  his 
appeal,  but  he  shall  take  no  part  therein.  The  decision  of  the  majority  of 
such  remaining  examiners  so  acting  shall  be  final  if  approved  by  the  chief  of 
the  district  police. 

SECTION  85.  An  engineer's  or  fireman's  license,  granted  under  the 
provisions  of  the  seven  preceding  sections  or  the  corresponding  provisions 
of  earlier  laws,  shall  be  placed  so  as  to  be  easily  read  in  a  conspicuous  place 
in  the  engine  room  or  boiler  room  of  the  plant  operated  by  the  holder  of 
such  license. 

SECTION  86.  The  boiler  inspection  department  of  the  district  police  shall 
act  as  examiners  and  enforce  the  provisions  of  the  eight  preceding  sections 


90  THE    SCHOOL    HOUSE. 

and  whoever  violates  any  of  the  provisions  of  said  sections  shall  be 
punished  by  a  fine  of  not  less  than  ten  nor  more  than  three  hundred  dollars 
or  by  imprisonment  for  not  more  than  three  months.  A  trial  justice  shall 
have  jurisdiction  of  complaints  for  violations  of  the  provisions  of  the  eight 
preceding  sections,  and  in  such  cases,  may  impose  a  fine  of  not  more  than 
fifty  dollars.  All  members  of  the  boiler  inspection  department  of  the 
district  police  shall  have  authority  in  the  pursuance  of  their  duty  to  enter 
any  premises  on  which  a  boiler  or  engine  is  situated,  and  any  person  who 
hinders  or  prevents  or  attempts  to  prevent  any  state  boiler  inspector  from  so 
entering  shall  be  liable  to  the  penalty  as  specified  in  this  section. 

[CHAP.  310,  ACTS  OF  1905.] 

********* 

SECTION  4.  All  acts  and  parts  of  acts  inconsistent  herewith  are  hereby 
repealed  :  provided,  however,  that  this  act  shall  not  apply  to  the  exemptions 
specified  in  section  seventy-eight  of  chapter  one  hundred  and  two  of  the 
Revised  Laws  or  that  such  repeal  shall  not  invalidate  any  license  granted 
under  the  acts  repealed;  and  licensees  holding  licenses  so  granted  shall  have 
the  powers  given  to  licensees  of  the  same  class  by  section  two  of  this  act. 

SECTION  5.  This  act  shall  take  effect  on  the  first  day  of  July  in  the  year 
nineteen  hundred  and  five.  [Approved  April  20,  1905.] 

[AMENDMENT  OF  1905.] 
[CHAP.  472,  ACTS  OF  1905.] 

AN   ACT    RELATIVE    TO   THE    INSPECT'ON   OF    STEAM    BOILERS. 

Be  it  enacted,  etc. ,  as  follows  : 

SECTION  1.  All  steam  boilers  of  more  than  three  horse  power,  except 
boilers  upon  locomotives,  in  private  residences,  or  under  the  jurisdiction  of 
the  United  States,  or  boilers  used  exclusively  for  agricultural,  horticultural 
or  creamery  purposes,  shall  be  inspected  either  by  the  district  police  or  by 
an  insurance  company  authorized  to  insure  boilers  within  the  Common- 
wealth. Such  inspection  shall  be  made  internally  and  externally  at  least 
once  in  each  year.  The  owner  or  user  of  any  steam  boiler  inspected  by  the 
district  police  shall  pay  to  the  inspector  the  sum  of  five  dollars  at  each 
internal,  and  two  dollars  for  each  external,  inspection  for  every  boiler 
so  inspected. 

SECTION  2.  Every  insurance  company  shall  forward  to  the  chief  of  the 
district  police  within  fourteen  days  after  each  internal  and  external 
inspection  a  report  of  every  boiler  so  inspected  by  it.  Such  reports  shall  be 
made  on  blanks  furnished  by  the  chief  of  the  district  police,  and  shall 
contain  any  recommendations  that  the  insurance  company  may  think  it 
desirable  to  make.  Notice  shall  be  given  by  the  insurance  company  or  the 
inspector  to  the  owner  or  user  of  the  boiler  inspected  of  the  pressure  at 
which  the  boiler  may  safely  be  operated. 

SECTION  3.  Any  insurance  company  failing  to  make  a  report  as  above 
provided  shall  be  fined  not  more  than  five  hundred  dollars  for  every  such 
failure.  Any  owner  failing  to  comply  with  the  requirements  of  the  insur- 
ance company  inspecting  his  boiler,  after  notice  by  the  chief  of  the  district 
police,  shall  be  liable  to  a  fine  of  not  more  than  five  hundred  dollars  for 
such  failure,  and  the  use  of  said  boiler  may  be  enjoined  in  the  manner 


THE    SCHOOL    HOUSE.  91 


provided  in  section  four  of  chapter  one  hundred  and  five  of  the  Revised 
Laws.  The  district  police  shall  have  authority  in  the  discharge  of  their 
duty  to  enter  upon  any  premises  where  steam  boilers  are  located,  for  the 
purpose  of  enforcing  the  provisions  of  this  act 

SECTION  4.     All  acts  and  parts  of  acts  inconsistent  herewith  are  hereby 
repealed.     [Approved  May  26, 


REVISED   LAWS   OF  MASSACHUSETTS. 

CHAPTER  105. 
Of  the  Inspection  of  Steam  Boilers. 

SECTION  1.  The  chief  of  the  district  police  shall  detail  ten  members  of 
the  inspection  department  of  the  district  police,  who,  under  his  direction, 
shall  inspect  stationary  steam  boilers  and  their  appurtenances,  shall  act  as 
examiners  of  engineers  and  firemen  and  shall  report  to  said  chief. 

SECTION  2.  Whoever  owns  or  uses  or  causes  to  be  used  a  steam  boiler, 
except  boilers  upon  locomotives,  in  private  residences,  under  the  jurisdiction 
of  the  United  States  or  under  the  periodically  guaranteed  inspection  of  com- 
panies which  have  complied  with  the  laws  of  this  Commonwealth,  boilers 
used  exclusively  for  agricultural,  horticultural  and  creamery  purposes  or 
boilers  of  less  than  three  horse  power,  shall  annually  report  to  the  chief  of 
the  district  police  the  location  of  such  steam  boiler. 

SKCTION  3.  Each  boiler  designated  in  the  preceding  section  and  not  therein 
excepted  shall  be  inspected  by  the  inspector  of  boilers  for  the  district  in  which 
said  boiler  is  located,  and  if  he  so  orders  the  owner  or  user  shall  have  the 
boiler  blown  off  dry  and  the  man-hole  and  hand-hole  covers  thereon  removed, 
ready  for  inspection,  upon  the  day  designated  by  the  inspector,  who  shall 
give  the  owner  or  user  of  said  boiler  fourteen  days  notice  in  writing  of  the 
day  upon  which  he  will  make  such  internal  inspection,  which  shall  not  be 
required  oftener  than  twice  a  year 

SECTION  4.  -  If,  upon  examination,  said  inspector  finds  the  boiler  to  be 
worthy  and'  in  safe  working  order,  with  the  fittings  necessary  to  safety,  and 
properly  set  up,  he  shall  grant  to  the  owner  or  user  thereof  a  certificate  of 
inspection,  and  thereupon  said  owner  or  user  may  use  the  boiler  mentioned 
in  the  certificate.  If  the  inspector  finds  that  the  boiler  is  not  in  safe  con- 
dition, or  is  not  provided  with  fittings  necessary  to  safety  or  with  fittings  not 
properly  arranged,  he  shall  withhold  his  certificate  until  the  boiler  and  fittings 
are  put  into  condition  satisfactory  to  him  ;  and  the  owner  or  user  shall  not 
operate  such  steam  boiler  or  cause  it  to  be  operated  until  such  certificate  has 
been  granted.  The  owner  or  user  of  such  boiler  shall  pay  to  the  inspector 
at  each  inspection  two  dollars  for  each  boiler  inspected.  The  supreme  judi- 
cial court  or  the  superior  court,  upon  the  application  of  the  inspector  of 
boilers  approved  by  the  chief  of  the  district  police,  shall  have  jurisdiction  in 
equity  to  restrain  the  owner  or  user  of  such  boiler  from  operating  it  without 
certificate. 

SECTION  5.  If  the  inspector  finds  that  the  owner  or  user  of  a  steam 
boiler  is  putting  too  much  pressure  upon  it,  he  may  fix  the  maximum  pres- 
sure to  be  carried  by  it  and  shall  prescribe  a  device  to  prevent  it  from  carry- 
ing more  than  the  maximum  pressure  designated,  which  shall  be  approved 
by  the  chief  of  the  district  police  and  which  the  owner  or  user  shall  place  or 
cause  to  be  placed  upon  said  boiler.  No  person  shall  in  any  manner  tamper 


92  THE    SCHOOL   HOUSE. 

with   such  device,  or  load  the  safety-valve  to  a  greater  pressure  than  that 
allowed  by  the  inspector. 

SECTION  6.  Whoever  violates  the  provisions  of  the  preceding  sections  of 
this  chapter  shall  be  punished  by  a  fine  of  not  more  than  five  hundred  dollars 
or  by  imprisonment  for  not  more  than  six  months,  or  by  both  such  fine  and 
imprisonment. 

SECTION  7.  The  mayor  and  aldermen  of  any  city  except  Boston,  or  the 
selectmen  of  a  town,  or  any  person  by  them  authorized,  may,  after  notice  to 
the  parties  interested,  examine  any  steam  engine  or  steam  boiler  therein, 
whether  fixed  or  portable ;  and  for  that  purpose  may  enter  any  house,  shop 
or  building ;  and  if  upon  such  examination  it  appears  probable  that  the  use 
of  such  engine  or  boiler  is  unsafe,  they  may  issue  a  temporary  order  to 
suspend  such  use  ;  and  if,  after  giving  the  parties  interested,  so  far  as  known, 
an  opportunity  to  be  heard,  they  adjudge  such  engine  or  boiler  to  be  unsafe 
or  defective  or  unfit  to  be  used,  they  may  pass  a  permanent  order  prohibiting 
the  use  thereof  until  it  is  rendered  safe.  If,  after  notice  to  the  owner  or 
person  having  charge  thereof,  such  engine  or  boiler  is  used  contrary  to  either 
of  such  orders,  it  shall  be  deemed  a  common  nuisance,  without  any  other 
proof  thereof  than  its  use. 

SECTION  8.  The  mayor  and  aldermen  and  selectmen  may  abate  and 
remove  a  steam  engine  or  steam  boiler  which  has  been  erected  or  used  con- 
trary to  the  provisions  of  the  preceding  section  in  the  same  manner  as  boards 
of  health  may  remove  nuisances  under  the  provisions  of  sections  sixty-seven, 
sixty-eight  and  sixty-nine  of  chapter  seventy-five. 

SECTION  9.  No  person  shall  manufacture,  set  up  or  use  a  steam  boiler 
or  cause  it  to  be  used  unless  it  is  provided  with  a  fusible  safety  plug,  made  of 
lead  or  some  other  equally  fusible  material  and  of  a  diameter  of  not  less  than 
one-half  an  inch,  placed  in  the  roof  of  the  fire  box,  if  a  fire  box  is  used,  and 
in  all  cases,  in  a  part  of  the  boiler  fully  exposed  to  the  action  of  the  fire,  and 
as  near  the  top  of  the  water  line  as  any  part  of  the  fire  surface  of  the  boiler. 

SECTION  10.  Whoever,  without  just  and  proper  cause,  removes  the  safety 
plug  from  a  boiler  or  substitutes  therefor  any  material  more  capable  of 
resisting  the  action  of  the  fire  than  the  plug  so  removed  shall  be  punished 
by  a  fine  of  not  more  than  one  thousand  dollars. 

SECTION  1 1 .  Whoever  manufactures,  sets  up  or  knowingly  uses  or  causes 
to  be  used  for  six  consecutive  days  a  steam  boiler,  unprovided  with  a  safety 
fusible  plug  as  described  in  section  nine,  shall  be  punished  by  a  fine  of  not 
more  than  one  thousand  dollars. 

SECTION  12.  The  provisions  of  the  five  preceding  sections  shall  not 
apply  to  a  boiler  for  which  a  certificate  of  inspection  issued  under  the  provi- 
sions of  sections  four  and  five  is  in  force 


CHAPTER   VI. 


STEAM-PIPES 

THE  success  of  a  steam-heating  apparatus  will  to  a  consid- 
erable   extent  depend    upon   the    proper    size,    location, 
grading,  dripping  and  valving  of  the  steam-pipes. 
In  the  earlier  installment  of  gravity  systems  of  steam-heating  in 
schoolhouses  trouble  was  often  caused  by  the  use  of  too  small  pipes, 
both  for  supply  and  return.     At  the  present  time  larger  pipes  are 
used  and  much  better  results  are  obtained. 

In  piping  indirect  radiators  the  following  may  be  considered  a 
safe  rule  for  size  of  supply  and  return  pipes  when  a  gravity  system 
is  used  and  steam  supplied  at  low  pressure,  five  pounds  or  less. 

TABLE  14. 


Square  Feet  of  Indirect  Radiators. 

Supply.     In  Inches. 

Return.     In  Inches. 

30  or  less 
30  to  50 

1 

n 

1 

1 

50  to  1  00 
100  to  100 

il 

2 

u 
ij 

It  is  not  advisable  to  make  indirect  radiator  stacks  with  more 
than  160  square  feet  of  radiating  surface,  and  140  is  to  be  preferred 
to  160  if  good  circulation  is  expected.  Three-quarter-inch  pipe  is 
the  smallest  that  should  be  used  for  return,  even  from  very  small 
radiators.  For  indirect  steam-heating  the  supply  pipes  should  have 
double  the  area  in  cross  section  of  those  supplying  direct  radiators. 

For  direct  radiation  steam  mains  and  risers  the  rule  adopted  by 
many  heating  contractors  is  TL  the  square  root  of  the  heating  sur- 
face in  square  feet  for  the  diameter  of  the  supply  pipes  in  inches ; 
or,  square  the  diameter  of  the  pipe  in  inches  for  the  number  of 
hundred  feet  of  direct  radiation  it  will  supply. 

By  using  pipe  one  size  larger  than  that  called  for  by  these  rules 
better  results  will  be  obtained.  Another  rule  is  to  divide  the  amount 
of  direct  heating  surface  in  square  feet  by  100,  divide  the  quotient 
by  .7854,  then  Extract  the  square  root  of  the  quotient  ;  the  result 
will  be  the  diameter  of  the  pipe  in  inches. 


94  THE    SCHOOL   HOUSE. 

As  a  general  rule,  return  pipes  should  be  one  size  smaller  than 
the  supply  pipes,  but  with  large  supply  mains  this  may  be  consid- 
erably reduced. 

By  using  large  and  well-covered  pipes  satisfactory  results  will  be 
obtained.  Too  frequently,  in  order  to  reduce  the  cost,  pipes  of  too 
small  diameter  are  used,  especially  for  indirect  steam  heating. 

The  supply  pipes  in  the  basement  of  a  schoolhouse  should  be 
well  covered  with  a  neat  non-heat-conducting  covering,  and  although 
the  first  cost  will  be  increased,  yet  the  results  therefrom  will  fully 
compensate  for  the  additional  expense. 

Care  should  be  taken  that  the  steam-pipes  are  properly  pitched, 
dripped  and  valved  in  order  to  secure  free  and  noiseless  circulation 
and  return  ;  that  they  are  properly  supported  on  roller  pipe  hangers 
and  proper  allowance  made  for  expansion  and  contraction. 

The*  main  return  pipes  should  be  provided  with  proper  check 
valves  and  shut-off s.  Valves  for  controlling  vent-flue  heating  should 
be  placed  in  the  basement.  Every  radiator,  heating  coil  or  stack 
should  be  fitted  with  a  supply  valve,  return  valve  and  automatic  air 
valve  properly  located.  Gate  or  angle  valves  are  to  be  preferred  to 
globe  valves.  Overhead  pipes  for  heating  the  basement  should  be 
properly  valved,  pitched  and  of  such  form  as  to  provide  for  expan- 
sion and  contraction,  and  hung  from  the  floor  timbers  of  the  first 
story  with  securely  fastened  roller  pipe  hangers  about  every 
eight  feet. 

Where  circulation  pipes  are  placed  on  the  walls  the  pipes 
should  be  well  straightened  and  secured  to  the  wall  by  hook  and 
expansion  plates,  fastened  to  wooden  strips  placed  not  more  than 
ten  feet  apart,  and  ample  provision  made  for  expansion  and  con- 
traction. 

Rising  main  and  return  pipes  should  be  straight  and  parallel, 
properly  valved  and  dripped,  and  where  pipes  pass  through  floors 
they  should  be  incased  through  the  full  depth  of  flooring  and  ceiling 
in  tin  tubes  with  flanged  iron  plates  screwed  to  the  floor,  and  with 
iron  ring  plates  or  flanges  securely  fastened  to  the  ceiling.  Where 
pipes  pass  through  wooden  partitions  tin  sleeves  and  flanged  plates 
should  be  used  and  if  through  brick  walls,  metal  collars  should  be 
provided.  Where  practicable,  return  pipes  should  be  laid  in  a 
properly-graded  brick  trench  having  a  covering  of  cast-iron  plates 
or  bluestone  flagging. 

Where  several  vertical  return  pipes  enter  the  main  return  they 
should  in  all  cases  be  carried  well  below  the  water-line  in  the  boiler 
before  they  unite  into  one  pipe. 


THE    SCHOOL   HOUSE.  95 

By  proper  arrangement  of  pipes  and  radiators  in  a  low-pressure 
gravity  return  system  the  condensation  may  be  easily  and  noise- 
lessly returned  to  the  boiler  without  the  use  of  traps  or  pumps. 

For  piping  connections  it  is  advisable  to  use  eccentric  fittings. 

A    two-pipe,    low-pressure,    gravity    return     system    of    steam- 
heating  is  to  be  preferred  for  schoolhouses  of  small  or  moderate" 
size.      In  large  buildings  a  double  mechanical  system  (one  having 
a  fan  supply  and  fan  exhaust) ,  or  a  combination  of  fan  (or  plenum) 
supply  and  gravity  exhaust,  is  to  be  preferred. 

Where  a  mechanical  system  is  used,  the  exhaust  from  the  engine 
should  also  be  used  for  heating.  A  mechanical  system  will  require 
the  use  of  fans,  engine,  pumps  or  traps,  governor,  tanks,  steam 
separator,  reducing  valves,  exhaust  head,  vapor  pipe,  etc. 

A  blow-off  tank,  properly  connected  with  a  dry  well  or  sewer 
and  properly  trapped,  should  be  provided  in  all  cases  where 
practicable.  A  valve  or  cock  should  be  provided  at  the  lowest 
place  in  the  system  to  draw  off  the  water  when  desired. 

RADIATORS. 

In  the  earlier  attempts  to  ventilate  school  buildings  by  indirect 
radiation  many  failures  occurred  on  account  of  an  insufficient 
amount  of  radiation  and  improperly  locating  and  casing  it ;  not 
ajlowing  sufficient  space  between  the  sections  for  a  liberal  quantity 
of  air  to  pass,  too  small  steam  supply  and  return  pipes,  and  not 
providing  adequate  means  for  regulating  the  temperature  of  air 
passing  the  radiators. 

It  has  been  found  in  actual  practice  (and  the  schoolrooms  in 
Massachusetts  are  now  generally  heated  accordingly)  that  to 
secure  the  best  results  under  varying  conditions  of  temperature  and 
wind  400  square  feet  of  cast-iron  radiating  surface  should  be 
supplied  for  an  ordinary  schoolroom  28  by  32  by  12  feet,  if 
situated  where  there  are  two  cold  exposed  walls  and  where  ample 
window  space  to  give  good  light  is  provided. 

This  should  be  divided  into  three  stacks,  one  of  100,  one  of  140 
and  one  of  160  square  feet;  or  one  of  120  and  two  of  140  square 
feet  each,  each  stack  to  be  separately  piped  and  valved,  in  order 
that  one,  two  or  three  sections  may  be  used  as  needed,  according  to 
the  outside  temperature.  The  100  feet  section  should  be  placed 
nearest  the  uptake  warm-air  flue. 

Where  there  is  but  one  exposed  wall,  and  on  the  southerly  side, 
380  square  feet  may  be  used  and  divided  into  three  stacks,  one  of 
100  and  two  of  140  square  feet  each. 


96  THE    SCHOOL   HOUSE. 

Cast-iron  radiators  having  an  extended  surface,  and  with  not  less 
than  one-half-inch  space  between  the  ends  of  the  pins  or  ribs  of  the 
several  sections,  are  now  generally  used  in  Massachusetts  school- 
houses. 

While  coils  or  radiators  made  of  steam-pipes  are  the  most  efficient 
radiating  surfaces,  yet,  on  account  of  the  cost  and  the  facility  of 
constructing  the  indirect  radiator  stacks,  cast-iron  is  now  generally 
used  with  gravity  systems. 

It  is  better  to  use  a  deep  radiator  than  to  double  bank  or  place 
one  section  above  another.  Cast-iron  extended  surface  radiators 
having  20  square  feet  of  radiating  surface  per  section  give  very 
satisfactory  results. 

The  sections  are  36  inches  long,  15 J  inches  high,  and  connected 
four  inches  from  center  to  center  of  the  sections,  tapped  for  two- 
inch  supply  and  return  pipes,  and  have  right  and  left  nipple  connec- 
tions. The  air-valve  measures  f  of  an  inch. 

When  more  than  one  school-room  receives  its  warm  air  through 
radiators  in  the  same  cold-air  room  the  radiator  stacks  for  each 
room  should  be  separated  by  galvanized-iron  divisions  extending 
about  20  inches  below  the  bottom  of  the  stacks.  Where  this  is  not 
done,  and  two  or  more  rooms  receive  air  from  the  same  cold-air 
room,  the  results  are  very  unsatisfactory,  as  one  room  may  receive 
much  more  than  its  fair  proportion  of  heat  and  air  at  the  expense 
of  another.  The  galvanized-iron  casings  for  indirect  radiators 
should  be  made  on  number  20  or  22  gauge  iron,  and  be  well 
stiffened  at  the  edges  and  corners. 

When  rooms  in  different  stories  of  the  building  receive  their  air 
supply  from  the  same  cold-air  room  the  radiators  for  the  first  story 
should  be  placed  nearest  the  cold-air  window,  in  order  that  they 
may  have  an  advantage  in  receiving  air  in  preference  to  the  rooms 
in  the  second  or  third  stories. 

The  supply  and  return  pipes  for  the  indirect  radiators  should  be 
well  protected  in  all  cases  where  they  come  inside  the  cold-air 
rooms  with  first-class  pipe  covering. 

The  valves  should  always  be  placed  outside  the  cold-air 
rooms. 

The  air-valves  give  better  results  when  placed  in  the  quarter 
turn  or  elbow  where  the  return  changes  to  a  downward  direction 
-than  when  placed  in  the  radiator  itself,  as  is  usually  done  where 
direct  radiators  are  used. 

The  bottom  of  the  radiators  should  not  be  cased,  but  left  entirely 
open,  as  much  more  even  distribution  of  air  is  obtained. 


THE    SCHOOL   HOUSE.  97 

In  the  earlier  indirect  radiator  work  it  was  customary  to  inclose 
the  radiators  on  all  sides  and  bring  the  air  in  at  one  end  of  the 
bottom  of  the  casing,  taking  it  out  at  the  top  of  the  opposite  end. 
This  does  not  give  as  good  results,  or  utilize  the  whole  of  the 
radiator  surface,  as  well  as  when  the  bottom  is  left  entirely  open 
and  a  cold-air  room  is  provided.  Under  some  conditions,  when 
the  first  method  is  used,  there  is  a  reversed  or  back  draft,  and  the 
writer  has  frequently  found  warm  air  going  out  of  the  building 
through  what  was  intended  to  be  the  cold-air  supply  opening. 

There  are  many  patterns  of  direct  radiators  in  use,  each  of  which 
is  claimed  by  the  manufacturer  to  have  various  good  points'.  Better 
results  are  obtained  when  a  tall  radiator  is  used  than  when  the 
stack  is  made  long  and  low. 

In  Part  II.  is  shown  a  direct-indirect  radiator,  designed  by  the 
late  John  T.  White,  which  has  been  successfully  used  where  a  full 
supply  of  air  is  not  required.by  indirect  radiators.  It  is  cased  and 
inclosed  in  a  manner  that  insures  a  better  utilization  of  heat  than 
is  possible  with  the  common  style  of  direct-indirect  radiators. 

In  many  schoolhouses  lines  of  1^-inch  steam-pipe  are  placed  on 
the  outside  walls  of  the  rooms,  and  are  used  at  night  and  before 
the  school  session  opens  to  quickly  warm  the  rooms.  In  rooms 
occupied  but  a  part  of  the  time,  such  as  assembly  halls  and  labora- 
tories, etc.,  this  is  a  good  provision  and  saves  fuel,  but  they  should 
not  be  used  in  schoolrooms  while  schools  are  in  session. 

Direct  radiators  are  often  used  to  good  advantage  in  schoolhouse 
corridors  and  in  teachers'  rooms. 

In  basement  rooms  the  heating  should  be  by  overhead  lines  of 
1J  inch  pipe,  unless  a  room  is  used  as  a  manual  training  room  or 
for  a  similar  purpose,  in  which  case  a  moderate  supply  of  air  from 
indirect  radiators  can  be  introduced  near  the  ceiling. 

In  using  wall  or  ceiling  pipes  special  attention  should  be  given 
to  properly  provide  for  expansion  and  contraction. 

There  should  be  at  least  two  feet  distance  between  the  bottom  of 
the  radiators  and  the  water-line  in  the  boiler  to  secure  a  eood 

o 

return  of  the  condensation  from  the  radiators.  If  a  greater  distance 
can  be  had  it  will  be  better,  and  danger  of  filling  the  radiators  with 
water  will  in  a  great  measure  be  prevented.  The  writer  has  seen 
cases  where  an  otherwise  well-designed  system  of  heating  has  been 
spoiled  by  not  allowing  sufficient  distance  between  the  bottom  of 
the  radiators  and  the  water-line  in  the  boiler. 

A  method  is  shown  in  Part  II.  of  arranging  radiators  to  be  used 
as  foot-warmers  and  for  warming  the  corridors.  These  stacks  are 


98  THE    SCHOOL    HOUSE. 

usually  made  up  of  120  square  feet  of  cast-iron  extended  surface  ra- 
diators, cased  in  galvanized  iron  and  hung  from  the  basement  ceiling. 
Very  satisfactory  results  are  obtained  when  two  lines  of  1 J  inch 
steam-pipe  are  placed  near  the  floor  in  the  corridor  and  under  the 
clothing  racks. 

AN  APPROXIMATE  RULE  FOR  ESTIMATING  THE  AMOUNT  OF 
INDIRECT  RADIATION 

For  a  fifty-seat  schoolroom  of  the  ordinary  size  (28  by  32  by  12 
feet)  with  a  gravity  system  of  heating  and  ventilation,  using  a  good 
indirect  radiator  with  ample  flues,  etc.,  and  natural  draft,  is  as 
follows  : 

50  (number  of  pupils)  X  30  (cubic  feet  of  air  per  pupil  per 
minute)  =  1500  (cubic  feet  of  air  per  minute). 

1500  (cubic  feet  per  minute)  X  60  (minutes  per  hour)  =90,000 
cubic  feet  of  air  supplied  per  hour. 

Air  at  zero  to  be  warmed  105  degrees  F.  90,000  (cubic  feet) 
X  105  (degrees)  =9,450,000  cubic  feet  of  air  warmed  one  degree. 
9,450,000  (cubic  feet)  -r-  50  (cubic  feet  warmed  one  degree  by  one 
heat  unit)  =  189,000  heat  units.  189,000  (heat  units)  -T-  1,000 
(heat  units  available  per  pound  of  steam)  =  189  pounds  of  steam 
condensed  to  water.  189  X  2  =378  square  feet  of  radiation.  In 
actual  practice  from  380  to  400  square  feet  of  cast-iron  indirect 
radiation  is  used  per  room.  This  allowance  is  made  on  account  of 
overrating  the  square  feet  of  surface  in  radiators  by  the  manufac- 
turers, for  air  leakage  in  rooms  and  to  meet  the  requirements  in 
exceedingly  cold  weather. 

While  this  may  not  be  an  approved  scientific  method  of  calcu- 
lating indirect  radiation,  and  may  by  some  be  called  a  u  rule  of 
thumb,"  yet  in  actual  practice  it  has  given  excellent  results  and 
may  be  considered  as  safe  as  some  more  scientific  and  theoretical 
formulas. 

AUTOMATIC  HEAT  CONTROL. 

Systems  of  automatic  heat  control  have  been  installed  in  a  con- 
siderable number  of  schoolhouses,  especially  in  large  buildings, 
and  if  they  can  give  the  results  claimed  for  them  they  will  be  of 
great  service.  Unfortunately,  in  many  cases  they  have  not  proved 
satisfactory,  and  in  a  short  time  complaints  were  made  that  the 
expected  results  had  not  been  obtained. 

The  first  attempts  to  automatically  control  mixing  dampers  were 
generally  complete  failures.  A  device  that  opens  wide  or  closes 


THE   SCHOOL    HOUSE.  99 

tight  the  mixing  damper  changes  the  temperature  from  all  warm 
to  all  cold  air,  and  uncomfortable  drafts  are  the  result. 

The  writer  has  seen  cases  where  the  temperature  of  the  incoming 
air  was  changed  from  over  100  degrees  F.  to  less  than  30  degrees 
F.  in  less  than  four  minutes  when  the  mixing  damper  was  auto-^ 
matically  operated.  When  the  damper  was  again  moved  the 
temperature  would  rise  to  the  high  point  in  but  little  over  five 
minutes.  This  was  especially  noticed  when  a  strong  wind  was 
blowing  into  the  cold-air  room.  When  the  mixing  damper  is 
moved  to  entirely  shut  off  the  warm  air,  except  what  little  leaks 
through  the  narrow  spaces  on  the  sides  and  top  of  the  mixing 
damper,  the  radiators,  if  steam  is  used,  soon  become  cold,  and  the 
cold  air  from  outside  passes  up  directly  into  the  schoolroom.  With 
furnaces  the  results  are  not  any  more  satisfactory. 

When  the  mixing  damper  is  moved  slowly  by  the  automatic 
control,  but  is  opened  wide  or  fully  closed,  the  results  are  not 
satisfactory. 

The  managers  and  agents  of  some  automatic  heat-controlling 
systems  frequently  guarantee  that  the  mixing-dampers  or  the  valves 
controlling  the  heat  supply  steam-pipes  will  be  operated  by  one 
degree  or  less  change  of  temperature,  as  indicated  by  the  ther- 
mometer attached  to  the  thermostat.  While  this  is  true  in  many 
cases,  yet  it  does  not  give  satisfactory  results  at  all  times.  When 
the  cold  air  is  admitted  by  the  mixing-damper,  or  the  steam-valves 
to  the  indirect  radiators  are  shut,  the  radiators  are  soon  cooled  and 
uncomfortable  drafts  are  felt,  and  as  the  thermostats  are  often 
placed  where  they  are  not  easily  and  quickly  acted  on  by  the 
incoming  air,  the  drafts  continue.  After  the  steam  has  been 
again  turned  on  by  opening  the  valves,  time  is  required  for  the 
radiators  to  again  become  warm  enough  to  give  off  sufficient 
heat  to  properly  warm  the  incoming  air,  the  cold  drafts  will 
continue  until  the  incoming  air  has  changed  the  temperature  at 
the  thermostat  enough  to  operate  the  valve  or  damper-controll- 
ing device.  This  is  often  several  minutes  after  the  valves  have 
been  opened. 

Most  of  the  automatic  heat-controlling  devices  are  of  delicate 
construction,  and  the  writer  has  seen  cases  where  an  accumulation 
of  lint  or  fine  fibers  has  caused  the  apparatus  to  become 
inoperative. 

Where  automatic  control  has  been  used  on  direct  radiators,  or 
where  a  combination  of  automatic  and  hand-control  has  been  used 
on  the  valves  of  different  sections  of  the  indirect  radiators,  more 


100  THE   SCHOOL   HOUSE. 

satisfactory  results  have  been  obtained  than  when  used  on  mixing- 
dampers. 

By  dividing  the  amount  of  indirect  radiation  for  a  school-room 
into  three  sections  and  using  hand  valves  on  two,  and  automatic  on 
one  section,  better  results  are  obtained  than  where  the  automatic  is 
used  on  all  three  sections. 

Automatic  control  is  sometimes  used  on  the  supplementary 
radiation  in  mechanical  systems  where  fans  or  blowers  are  used. 
If  it  is  to  be  used  in  a  mechanical  system  the  results  will  be  better 
if  the  primary  coils  or  stacks  are  provided  with  all  or  nearly  all 
hand-controlled  valves,  and  the  automatic  used  on  the  supple- 
mentary coils  or  stacks  or  direct  radiators  or  wall  coils,  if  such 
are  provided. 

When  used  on  hot-water  radiators  the  change  of  temperature  is 
not  as  rapid  as  with  steam  radiators. 


CHAPTER  VII. 


FURNACES. 

THE  use  of  furnaces  for  heating  and  ventilating  school 
buildings  should  be  confined  to  small  buildings  not 
exceeding  eight  rooms. 

In  large  buildings  the  number  of  furnaces  required  will  occupy 
so  much  of  the  basement  and  there  will  be  so  many  fires  to  attend 
to  that  a  steam-heating  apparatus  can  be  more  advantageously 
installed. 

When  furnaces  are  used  in  school  buildings  or  places  of  assem- 
blage they  should  be  located  where  the  warm-air  flues  or  ducts  will 
be  as  nearly  perpendicular  as  possible.  Long  and  nearly  hori- 
zontal runs  of  pipe  should  be  avoided. 

It  is  advisable  that  schoolhouse  furnaces  should  be  of  heavy 
castings  having  as  few  joints  as  possible.  There  are  several  makes 
of  furnaces  specially  designed  for  schoolhouse  heating  and  of  extra 
large  size. 

A  cast-iron  furnace  having  a  fire-pot  of  34  to  35  inches  diameter 
should  be  provided  for  two  school-rooms  of  the  ordinary  size 
(28  by  32  by  12  feet). 

Attempts  to  use  smaller  furnaces  or  to  heat  more  than  two 
ordinary  size  school-rooms  from  one  furnace  have  resulted  in 
failures  to  give  the  required  amount  of  heat,  and  now  it  is  seldom 
that  a  contractor  intending  to  do  good  work  will  attempt  to  heat 
and  ventilate  more  than  two  schoolrooms  with  one  furnace,  even  if 
the  furnace  is  of  the  largest  kind  manufactured. 

In  selecting  a  furnace,  one  with  a  nearly  straight-sided  fire-pot  is 
to  be  preferred  to  one  that  has  sloping  or  tapering  sides.  In  the 
latter  case  the  accumulation  of  ashes  at  the  side  of  the  fire -pot 
retards  the  passage  of  heat,  and  the  fire  is  not  as  easily  cleaned  as 
when  the  sides  are  nearly  perpendicular. 

Furnaces  provided  with  triangular  revolving  grates  are  to  be 
preferred  to  those  having  oscillating  ones,  as  the  triangular  grates 
will  cut  the  ashes  and  clinkers  and  remove  them  more  effectually 
than  will  other  patterns  of  grates. 


102  THE    SCHOOL   HOUSE. 

Wrought-iron  or  steel-plate  furnaces  with  fire-brick  lining  have 
iiqt  given  as  satisfactory  results  as  those  of  cast-iron  which  have  a 
good  thickness  of  metal. 

It  is  claimed  for  wrought-iron  furnaces  that  they  do  not  allow 
gas  to  escape  through  the  metal,  and  that  it  will  through  highly- 
heated  cast-iron. 

While  it  is  true  that  under  some  conditions  gas  will  to  a  limited 
extent  escape  through  highly -heated  cast-iron,  yet  with  an  ample 
supply  of  air  passing  to  the  school-rooms  and  a  large  furnace  of 
heavy  castings,  not  overheated,  the  amount  of  gas  escaping  will  be 
so  very  small  that  it  may  be  practically  disregarded. 

The  escape  of  gas  through  heated  cast-iron  is  more  a  matter  of 
advertising  the  special  advantages  claimed  for  some  furnaces  than 
of  real  danger  to  the  occupants  of  a  school-room. 

It  is  essential,  however,  that  there  be  as  few  pieces  as  practicable, 
and  that  the  joints  be  made  as  tight  as  possible. 

By  proper  attention  to  the  draft  and  check  dampers  the  amount 
of  escaping  gas  can  be  reduced  to  a  point  at  which  no  ill  effects 
can  be  observed. 

If  it  is  suspected  that  gas  is  escaping  from  the  combustion 
chamber  into  the  warm-air  supply  for  the  room,  an  old  rubber  or 
a  leather  shoe  may  be  thrown  into  the  fire,  and  when  the  shoe  is 
well  ablaze,  all  the  dampers  and  drafts  being  closed,  it  will  soon 
be  determined  whether  or  not  gas  is  passing  into  the  room.  The 
odor  of  the  old  shoe  will  be  noticeable  at  the  warm-air  inlet  if  any 
considerable  amount  of  gas  is  coming  in. 

Several  designs  of  cast-iron  furnaces  made  of  vertical  sections 
with  extended  surfaces,  and  held  together  with  bolts  through 
flanges  of  the  sections,  have  been  used  in  school  buildings  ;  but  they 
are  not  a  desirable  type,  as  there  are  too  many  joints,  some  of 
which  may  warp  and  open  up  a  passage  for  the  unconsumed  products 
of  combustion  to  pass  through  and  mingle  with  the  air  supply  for 
the  schoolrooms.  This  class  of  furnace  is  now  seldom  installed  in 
Massachusetts  schoolhouses. 

The  writer  has  seen  a  number  of  these  furnaces,  which  by  exces- 
sive firing  by  the  janitors  have  so  warped  at  the  flanges  and  where 
the  bolts  have  so  rusted  or  been  destroyed  by  heat,  that  openings, 
sometimes  one-half  inch  or  more  wide,  have  been  made  through 
which  the  unconsumed  products  of  combustion  have  passed  in  a 
sufficient  quantity  to  badly  contaminate  the  air  in  the  school-rooms. 

Some  cast-iron  furnaces  also  have  a  radiator  attachment  of  thin 
sheet-iron  or  steel  which  in  a  few  years  will  become  corroded 


THE    SCHOOL   HOUSE.  103 

sufficiently  to  open  large  holes  for  the  escape  of  gas.  Where  these 
radiator  attachments  are  used  the  sheet  metal  should  be  of  sufficient 
thickness  to  last  as  long  as  the  cast-iron  fire-pot. 

In  installing  a  furnace  for  schoolhouse  heating  special  attention 
should  be  given  to  having  sufficient  space  between  the  heatifig 
surface  and  the  casing  to  allow  the  passage  of  a  large  quantity  of 
air  at  a  moderate  temperature,  rather  than  to  heat  a  small  quantity 
to  a  high  temperature. 

It  is  advisable  to  use  brick-set  furnaces  in  schoolhouses  instead 
of  the  metal-cased  portable  type  generally  used  for  dwelling-house 
heating,  which  usually  have  an  insufficient  space  between  the 
casing  and  the  fire-pot.  When  the  portable  type  of  furnace  is 
used  in  schoolhouses  a  special  and  large  casing  should  be  provided. 

Smoke-pipes  for  furnaces  should  be  of  ample  size  and  as  short 
as  possible  to  reach  the  chimney  smoke-flue,  having  as  few  turns 
or  elbows  as  practicable,  and  fitted  with  one  or  more  dampers  to 
regulate  the  draft. 

When  soft  coal  is  burned,  the  ordinary  size  schoolhouse-furnace 
smoke-pipe  should  be  at  least  one  inch  larger  diameter  than  when 
hard  coal  is  used. 

Where  it  becomes  necessary  to  take  the  smoke  from  two  furnaces 
into  one  chimney  flue,  which  is  not  a  desirable  arrangement,  the 
pipes  should  be  united  by  a  breeches  connection  into  one  large 
pipe  before  it  enters  the  chimney,  and  each  furnace  smoke-pipe 
should  have  its  own  damper. 

A  pit  should  be  provided  under  the  furnace  which  should  be  at 
least  t\vo  feet  deep  and  equal  in  width  to  the  diameter  of  the 
furnace  casing.  This  will  allow  the  air  to  circulate  around  the  fire- 
pot  and  will  more  effectively  distribute  it  against  the  heated  surface 
of  the  fire-pot.  When,  as  has  frequently  been  the  case,  the  air  is 
admitted  through  an  opening  in  one  side  of  the  furnace  casing  and 
nearly  opposite  the  fire-pot,  the  results  are  not  satisfactory,  and 
but  part  of  the  heated  surface  is  utilized  in  the  most  effective 
manner. 

The  air  for  mixing  with  the  air  from  the  furnaces  for  regulating 
the  temperature  of  the  school-room  should  never  pass  under  the 
furnace,  but  should  be  entirely  outside  the  space  between  the  fire- 
pot  and  casing. 

When  the  air  for  mixing  is  taken  under  the  furnace  the  result 
will  surely  be  a  failure  to  secure  proper  temperature  for  the  air 
entering  the  school-room.  The  air  will  follow  the  line  of  least 
resistance,  which  is  up  near  the  heated  surface  of  the  fire-pot,  and 


104  THE   SCHOOL   HOUSE. 

will  not  pass  under  the  furnace  and  into  the  space  intended  for  it 
to  reach  the  mixing-valve. 

When  the  warm  air  is  shut  off  by  the  mixing-valve  it  will  be 
heated  and  expanded  in  the  hot-air  chamber,  and  will  back  down 
and  out  into  the  space  intended  for  the  cold  air  for  mixing.  It 
will,  when  the  mixing-valve  is  open  for  warm  air,  follow  the  line  of 
least  resistance,  and  the  school-room  will  become  overheated  when 
there  is  a  strong  fire  in  the  furnace.  In  moderate  weather  under 
such  conditions  it  will  be  impracticable  to  furnish  the  required 
amount  of  air  without  uncomfortably  overheating  the  school-room. 

A  furnace  smoke-pipe  should  never  pass  through  a  cold-air  room 
when  possible  to  avoid  doing  so.  In  case  of  a  smoke-pipe  rusting 
and  opening  holes  in  the  pipe,  or  if  the  pipe  is  not  well  and  tightly 
jointed,  there  is  liability  of  the  unconsumed  products  of  combustion 
passing  into  the  school-rooms.  The  cold  air  also  has  a  tendency  to 
reduce  the  heat  of  the  escaping  gases  and  retard  the  draft.. 

The  writer  has  seen  cases  where  the  smoke-pipe  was  intention- 
ally twisted  and  made  into  what  may  have  been  intended  to  be 
similar  to  a  trombone  coil,  for  the  purpose,  as  alleged,  of  utilizing 
the  waste  heat  in  the  smoke-pipe  for  warming  the  air  in  the 
cold-air  room. 

The  result  was,  however,  that  it  made  a  good  condenser,  and 
the  condensed  smoke  and  gases  dripped  down  through  the  joints  in 
the  pipe  into  the  cold-air  room  and  assisted  in  contaminating  the 
fresh  air  in  addition  to  what  was  done  by  the  gas  escaping  from 
the  combustion  chamber  through  openings  between  sections  of  the 
furnace.  The  condensation  also  assisted  greatly  to  destroy  the  iron 
of  the  smoke-pipe. 

The  furnace  should  be  placed  below  the  school-room  rather  than 
under  a  corridor  or  clothing  room,  in  order  that  the  warm  air  may 
pass  up  the  front  side  of  the  heat  shaft  instead  of  on  the  back,  and 
thus  avoid  uncomfortable  drafts  in  the  school-room. 

The  cold  air  for  mixing  should  always  pass  up  on  the  rear 
side  of  the  heat  shaft. 

When  for  structural  reasons  the  furnace  must  be  placed  other 
than  under  the  school-room,  the  furnace  should  be  placed  low 
enough  to  enable  the  cold  air  for  mixing  to  be  taken  over  the  top 
of  the  furnace  .casing  or  setting  and  to  enter  the  heat  shaft  on  the 
rear  side.  The  proper  location  of  the  furnace  is  a  matter  that 
should  be  carefully  considered,  as  nothing  will  contribute  more  to 
obtaining  satisfactory  results  as  to  temperature  than  will  its  proper 
location  with  relation  to  the  warm-air  flues. 


THE    SCHOOL   HOUSE.  105 

Pipes  for  conveying  air  to  floor  registers  in  corridors  or  clothing 
rooms  should  not  be  taken  from  the  warm-air  chamber  of  a  furnace 
when  the  warm  air  for  the  school-rooms  is  taken  into  the  room 
above  the  floor.  Where  this  is  done  the  results  are  not  satisfactory  ? 
as  the  air,  instead  of  passing  to  the  floor  registers,  will  frequently 
be  carried  up  the  warm-air  flues  into  the  school-rooms,  and  a 
reversal  of  the  air  current  will  result.  This  will  happen  whenever 
the  air  supply  for  the  furnace  is  checked  or  partly  shut  off  at  the 
cold-air  opening  into  the  fresh-air  room.  The  air  will  be  taken 
from  the  corridor  or  clothing-room  to  the  school-room  instead  of 
from  the  furnace  to  the  corridor. 

A  liberal  sized  cold-air  room  should  always  be  provided  for 
furnaces  in  schoolhouses.  It  will  to  a  great  extent  prevent  back 
drafts  by  suction  of  the  wind  outside,  and  will  give  a  much  better 
supply  of  air  under  all  conditions  than  will  the  ordinary  cold-air 
box. 

The  windows  in  the  cold-air  room  should  be  hinged  from  the 
top  and  the  opening  be  covered  with  a  stout  wire  grill  or  netting. 

If  heat  is  required  for  corridors  or  small  rooms  it  is  much  better 
to  provide  a  small  and  separate  furnace  for  this  purpose,  providing 
steam  cannot  be  used. 

In  the  best  and  most  satisfactory  work  now  being  done  in  Massa- 
chusetts, where  furnaces  are  used  for  heating  class-rooms,  a  small 
steam  boiler  is  used  to  furnish  heat  for  the  vent-flues  and  also  for 
warming  the  corridors  and  small  rooms. 

Twin  connected  furnaces  are  sometimes  installed  in  schoolhouses ; 
but  the  results  obtained  are  not  as  satisfactory  as  where  each 
furnace  has  an  independent  setting. 

The  distribution  of  air  is  not  always  good  and  depends  upon 
which  furnace  is  heated,  as  is  the  case  when  only  one  furnace  is 
in  use  in  moderate  weather. 

When  a  fan  is  used  and  both  furnaces  are  heated,  the  results  are 
much  better  than  by  a  gravity  system  using  only  one  of  the  twin 
furnaces  at  a  time. 

The  use  of  a  combination  of  furnace  and  hot-water  heating  is 
not  recommended  for  schoolhouses.  While  often  giving  satisfac- 
tion in  a  dwelling-house,  the  conditions  existing  in  a  schoolhouse 
are  not  such  as  to  justify  the  use  of  a  hot-water  attachment  in  the 
furnace. 

It  frequently  happens  that  during  cold,  weather  the  janitor  will 
allow  the  fires  to  go  out  between  the  close  of  the  Friday  P.M. 
session  and  the  opening  of  the  Monday  A.M.  session,  or  that  during 


106  THE    SCHOOL   HOUSE. 

the  winter  vacation  the  fires  will  not  be  kept  up.  In  such  cases 
the  water  attachment  may  become  frozen  and  pipes  or  radiators 
burst. 

Where  electric  power  is  obtainable  at  a  reasonable  price  a  com- 
bination of  fan  and  furnace  may  be  used,  and  excellent  results 
obtained,  especially  in  mild  weather. 

A  good  sized  disk  fan  run  at  a  comparatively  low  velocity,  if 
properly  located  between  the  cold-air  room  and  furnace,  will  give 
very  satisfactory  results  and  can  quickly  warm  the  building  by 
rotating  the  air  through  it  before  the  opening  of  the  school  session. 

Where  electric  power  is  not  easily  obtained  a  gas  engine,  and  in 
some  cases  a  water-motor,  has  been  used  to  drive  the  fan.  Neither 
of  these  is  as  satisfactory  as  electric  power,  especially  in  small 
buildings. 

The  noise  and  the  escape  of  the  products  of  combustion  into  the 
building  are  serious  objections  to  the  use  of  a  gas  engine. 

The  cost  of  water  in  cities  and  towns  having  a  water  supply 
system  is  such  as  to  practically  prohibit  the  use  of  the  water-motors 
for  running  fans. 

STACK  HEATERS. 

When  steam  is  not  available  for  heating  vent-flues,  a  stove  or 
small  furnace  called  a  "  stack-heater"  is  used  to  raise  the  tempera- 
ture in  the  vent-shaft  and  cause  a  good  outflow  of  foul  air.  This 
stack -heater  is 'usually  placed  in  the  basement  so  that  it  may  be 
easily  tended  and  to  prevent  the  annoyance  of  ashes  and  dirt  on  the 
schoolroom  floor.  The  air  from  the  first  story  rooms  is  brought 
down  in  galvanized-iron  ducts  (or  sometimes  brick  ducts)  and 
enters  the  vent-shaft  below  the  stack -heater. 

When  a  stack -heater  is  used  the  foul  air  from  the  schoolrooms  is 
taken  out  through  one  common  vent-shaft  having  a  cross-sectional 
area  of  20  square  feet  for  four  50-seat  schoolrooms,  which  are  as 
many  rooms  as  it  is  advisable  to  vent  through  one  shaft.  The  two 
rooms  in  the  second^  story  should  be  vented  directly  into  the 
common  shaft. 

A  stack -heater,  having  a  fire-pot  about  22  inches  in  diameter 
and  grate  20  inches  in  diameter,  is  generally  used  to  ventilate  a 
school  building  where  four  school-rooms  and  two  corridors  are 
vented  into  the  same  shaft. 

A  stack-heater  for  sanitary  closets  in  school  buildings  containing 
up  to  eight  rooms,  and  with  a  16 -inch  diameter  fire-pot  and  14- 
inch  grate,  is  commonly  used  in  the  sanitary  vent-flues.  While 


THE   SCHOOL   HOUSE.  107 

smaller  grate  surface  may  theoretically  be  used  in  stack-heaters,  yet 
with  too  small  a  fire-pot  the  fire  is  liable  to  go  out  for  want  of 
proper  attention  by  the  janitor. 

The  stack-heater  should  be  placed  so  that  the  air  for  furnishing 
the  draft  for  the  fuel  is  taken  from  outside  the  shaft. 

When  the  stack-heater  is  placed  entirely  within  the  vent-shaft 
and  receives  its  air  for  draft  from  within  the  shaft  and  is  tended 
through  a  door  in  the  shaft,  the  results  are  not  satisfactory. 

Where  separate  vent-flues  are  provided  from  each  of  several 
rooms  it  is  not  practicable  to  use  a  stack-heater,  and  steam  heat 
must  be  employed. 


CHAPTER   VIII. 


JANITORS. 

SUCCESS  or  failure  in  obtaining  satisfactory  results  with  a 
well-designed  system  of  heating  and  ventilation  often 
depends  upon  the  care  and  good  judgment  exercised  by 
the  janitor  or  engineer  having  charge  of  the  apparatus. 

Complaints  have  frequently  been  made  that  the  heating  and 
ventilation  of  a  school  building  were  not  satisfactory ;  that  the 
rooms  were  too  warm  or  too  cold ;  that  uncomfortable  drafts  were 
felt;  that  the  air  was  bad,  etc. 

On  inspection,  these  complaints  were  often  well  founded,  and 
on  looking  for  the  cause  it  was  very  frequently  discovered  to  be  the 
fault  of  the  engineer  or  janitor  in  charge,  and  not  of  the  apparatus 
installed  in  the  building. 

A  janitor  or  engineer  who  is  negligent,  or  not  informed  as  to  the 
proper  way  of  operating  the  apparatus  under  his  control,  can 
easily  give  a  well-designed  and  a  properly-installed  system  a 
bad  name. 

If  heating  and  ventilating  engineers  and  contractors /vho  install 
systems  in  school  and  public  buildings  will  see  that  the  engineer  or 
janitor  is  properly  instructed  as  to  his  duties  when  first  taking 
charge,  they  will  find  it  greatly  to  their  advantage ;  not  only  as  to 
the  reputation  their  work  will  have,  but  they  may  be  saved  expense 
in  responding  to  calls  to  come  and  see  what  is  the  matter  with 
the  apparatus. 

Printed  instructions  provided  by  the  contractor  or  engineer  who 
designed  the  work,  if  posted  in  the  boiler  or  furnace-room,  will 
more  than  pay  the  expense  of  printing  and  posting,  and  will 
save  annoyance. 

A  janitor  who  understands  the  system  and  properly  manages  it 
will  not  only  give  better  satisfaction  to  the  school  authorities,  but 
will  in  many  cases  make  a  considerable  saving  in  the  expense 
of  operation. 

An  incompetent  or  lazy  janitor  may  cause  an  excessive  waste 
of  fuel  and  perhaps  serious  damage  to  the  apparatus  under  his 
charge. 


THE    SCHOOL   HOUSE.  109 

A  janitor  in  a  school  or  public  building  should  be  able  to  pass 
an  examination  as  to  his  fitness  and  ability  to  manage  the  modern 
appliances  for  heating  and  ventilating  a  schoolhouse  or  public 
building. 

More  is  required  of  a  janitor  than  the  ability  to  shovel  coal  ifito- 
a  furnace  or  under  a  steam-boiler,  or  to  see  that  a  proper  amount 
of  water  is  in  the  boiler.  Good  judgment  and  a  thorough  knowl- 
edge of  the  apparatus  is  essential. 

Besides  regulating  the  fires  properly  by  having  good  and  clean 
fires  in  cold  weather  and  light  fires  in  m'oderate  weather,  and,  with 
a  steam-heating  system,  seeing  that  the  proper  amount  of  radiation 
is  in  use,  it  is  of  the  utmost  importance  that  the  inlets  for  fresh 
air,  the  mixing-damper  for  regulating  the  temperature  of  the  air 
supplied  to  the  class-rooms,  the  heat  or  fans  for  the  ventilating 
ducts,  and  the  dampers  for  regulating  the  outflow  of  foul  air, 
should  be  properly  understood  and  managed. 

In  a  mechanical  (fan)  system  care  should  be  taken  that  the  fans 
are  run  at  a  proper  speed  and  at  the  proper  time. 

It  is  very  important  that  the  windows  admitting  air  to  the  cold- 
air  rooms,  where  the  indirect  radiators  or  furnaces  are  located,  are 
properly  opened  or  partly  closed,  as  may  be  required  by  the  con- 
stantly varying  conditions  of  temperature  and  wind.  These 
windows  should  be  hinged  at  the  top  and  open  inward  in  order 
that  the  air  may  be  deflected  downward  and  distributed  through  the 
cold-air  room. 

The  stacks  of  indirect  radiators  or  the  furnace  should  never 
be  placed  so  close  to  the  window  that  the  window  cannot  be 
opened  to  its  full  capacity.  When  a  gravity  system  is  used  the 
windows  in  the  cold-air  rooms  should  have  an  opening  equal  to 
the  combined  area  of  the  several  ducts  leading  from  the  cold-air 
room. 

With  a  mechanical  system  in  a  large  building  the  area  of  these 
windows  may  be  less  than  in  a  gravity  system. 

In  mild  'weather  and  when  there  is  but  little  wind  they  should 
be  kept  wide  open  during  the  school  session;  in  very  cold  or 
windy  weather  they  should  be  partly  closed ;  but  under  no 
circumstances  should  they  be  entirely  closed  when  school  is  in 
session . 

If  opened  too  wide  when  a  strong  wind  is  blowing  into  the  cold- 
air  room,  more  air  will  be  supplied  than  is  required  or  can  be 
properly  warmed,  and  uncomfortable  drafts  will  be  felt  in  the 
school-rooms. 


110  THE    SCHOOL    HOUSE. 

If  closed  too  much,  a  sufficient  supply  of  fresh  air  will  not  be 
furnished  and  the  air  in  the  school-rooms  will  be  vitiated  to  an 
objectionable  degree. 

When  on  the  leeward  side  of  the  building  they  should  be  opened 
wider  than  when  they  are  on  the  windward  side. 

Each  window  in  the  cold-air  rooms  should  be  provided  with  a 
stout  cord  or  chain  and  pulley  and  means  for  fastening  the  same, 
in  order  that  the  window  may  easily  be  opened  or  closed  to  any 
desired  position. 

It  is  also  advisable  to  hold  the  window  in  the  desired  position 
and  not  allow  it  to  fly  up  or  down  by  the  action  of  the  wind. 
This  can  be  done  by  another  cord  or  chain. 

Mixing-valves  or  dampers  are  placed  in  the  fresh-air  ducts 
which  lead  to  the  several  rooms,  by  means  of  which  the  air  is 
allowed  to  pass  through  the  stacks  of  indirect  radiators  or  along 
the  heating  surface  of  the  furnace,  or  is  caused  to  by-pass  without 
going  through  the  heaters. 

By  the  use  of  mixing-dampers  the  temperature  of  the  air  supplied 
to  the  school-rooms  can  be  regulated  without  materially  reducing  the 
supply.  * 

When  valved  registers  are  used  and  the  room  becomes  too  warm 
the  heat  is  shut  off  as  is  also  the  supply  of  air  at  the  same  time. 

The  teachers  as  well  as  the  janitor  frequently  operate  the  mixing- 
valves  and  dampers,  and  should  also  be  instructed  in  their  use. 

It  often  happens  that  when  the  school-room  becomes  overheated 
the  chain  operating  the  mixing-valve  is  pulled  in  such  a  manner  as 
to  almost  entirely  shut  off  the  warm  air  and  turn  on  the  cold  air. 
Cold  air  is  then  admitted  to  the  room  and  uncomfortable  drafts  are 
caused,  then  when  the  room  has  become  too  cool  the  chain  is 
moved  in  the  opposite  direction  and  the  room  is  soon  overheated 
again.  If  this  is  continued  the  teacher  or  janitor  will  be  kept  busy 
trying  to  keep  the  room  at  a  comfortable  temperature. 

If,  however,  when  the  temperature  of  the  room  begins  to  rise  or 
fall  below  the  desired  point  (68  to  70  degrees  F.)  the  mixing- 
damper  chain  is  moved  but  a  little  at  a  time  —  say  from  one-half  to 
one  inch — there  will  be  little  difficulty  in  maintaining  the  desired 
temperature  if  the  fires  and  the  windows  in  the  cold-air  rooms  are 
properly  managed.  The  mixing-valve,  after  having  been  once 
properly  adjusted,  may  not  require  to  be  moved  during  the  whole 
or  greater  part  of  the  session. 

Two  or  three  pieces  of  thin  or  narrow  ribbon  —  about  one- 
quarter  of  an  inch  wide  and  about  ten  inches  long  (red,  white  and 


THE    SCHOOL    HOUSE.  Ill 

blue  would  be  appropriate  colors)  tied  into  the  wire  grill  at  the 
warm-air  inlet,  about  two-thirds  the  distance  up  from  the  bottom 
to  the  top  and  in  the  center  of  the  wire  grill,  will  be  of  great  assis- 
tance to  the  teacher  in  determining  whether  or  not  a  proper  amount 
of  fresh  air  is  being  supplied  to  the  school-room. 

If  the  ribbon  does  not  blow  out  or  flutter  it  will  indicate  a  defi- 
ciency in  the  fresh-air  supply. 

A  metallic  thermometer  about  four  inches  in  diameter,  which 
has  an  indicator  hand,  will,  if  placed  on  or  in  the  wire  grill  near 
the  ribbon,  enable  the  teacher  or  janitor  to  place  the  mixing-valve 
in  the  right  position. 

As  the  outflow  of  air  from  a  room  through  the  exhaust  flues  or 
ducts  is  caused,  in  a  gravity  system,  by  the  difference  between  the 
temperature  of  the  external  and  internal  air,  and  also  by  the  force 
of  the  wind  blowing  across  the  top  of  the  ventilating  stack  or  flue, 
some  means  of  meeting  the  constantly-varying  conditions  of  tem- 
perature and  wind  must  be  provided. 

In  a  mechanical  system  provision  should  be  made  for  regulating 
the  flow  of  air  through  the  several  ducts  and  flues. 

In  both  the  gravity  and  mechanical  systems  dampers  should  be 
placed  at  the  outlet  from  each  ventilated  room. 

The  heat  in  the  vent-flues  should  be  used  in  a  manner  directly 
opposite  from  that  used  for  warming  the  rooms.  The  greater  the 
difference  between  the  temperature  of  the  outside  and  inside  air, 
the  less  will  be  the  amount  of  heat  required  in  the  vent-flues. 

In  very  cold  and  windy  weather  no  heat  may  be  needed  in  the 
vent-flues,  and  the  dampers  in  the  outlets  from  the  rooms  may  often 
be  partly  but  never  entirely  closed  while  school  is  in  session. 

In  mild  and  calm  weather  the  dampers  should  be  wide  open  and 
heat  maintained  in  the  vent-flue  heaters.  The  warmer  the  weather, 
the  more  heat  will  there  be  required  in  the  vent-flue  heaters. 

Pieces  of  ribbon  similar  to  those  on  the  warm-air  inlet  should 
be  provided  for  the  outlets,  but  they  should  be  placed  on  the  inner 
side  of  the  grill.  If  they  flutter  into  the  duct  it  will  indicate  an 
outflow  of  air  from  the  room.  If  they  blow  back  or  rest  against 
the  grill  it  will  indicate  a  reversed  draft  or  no  draft. 

In  cold  weather,  after  the  school  session  has  closed,  sufficient 
time  should  be  allowed  to  flush  out  the  room  with  fresh  air. 

The  dampers  at  the  outlets  should  then  be  closed  and  the  heat 
in  the  vent-ducts  shut  off. 

Leaving  the  dampers  in  the  vent-ducts  open  at  night  will  cause 
a  waste  of  fuel  and  unnecessary  cooling  of  thfc  rooms. 


112  THE    SCHOOL   HOUSE. 

In  warm  weather,  when  no  heat  is  supplied  by  the  warm-air 
inlets,  the  dampers  may  remain  open  at  night. 

After  school  has  been  dismissed  for  the  day  and  the  class-rooms 
have  been  flushed  out  with  fresh  air  from  the  warm-air  inlets  the 
windows  admitting  air  to  the  cold-air  rooms  in  the  basement  should 
be  closed,  as  should  also  the  dampers  in  the  vent-flues.  The  rotat- 
ing registers  in  the  floor  above  the  cold-air  rooms,  as  well  as  the 
doors  from  the  several  class-rooms,  should  then  be  opened  and  the 
air  rotated  through  the  building  by  means  of  the  indirect  radiators 
or  furnaces.  The  fires  can  then  be  banked  and  checked  for  the 
night. 

In  cold  weather,  if  direct  radiation  has  been  provided  in  the 
class-rooms  in  addition  to  the  indirect  radiation,  the  direct  radiation 
should  be  turned  on  and  kept  on  till  a  short  time  before  the  opening 
of  the  morning  session. 

If  plenum  fans  are  used  they  should  be  started  in  season  to 
thoroughly  warm  the  building  by  rotating  the  air  before  the  opening 
of  the  morning  session. 

The  direct  radiation  in  class-rooms  should  not  be  used  while 
school  is  in  session,  unless  the  class-rooms  cannot  be  heated 
without  it. 

The  heat  in  the  sanitary  vent-flues  should  be  kept  up  at  all  times, 
except  perhaps  in  very  cold  and  windy  weather. 

The  dampers  in  the  corridor  vents  should  be  closed  at  night. 

Care  should  be  taken  not  to  open  the  windows  in  the  sanitary 
rooms  and  allow  the  wind  to  blow  in,  as  the  odors  may  under  some 
conditions  be  driven  out  of  these  rooms  into  other  parts  of  the 
building. 

It  is  much  better  to  depend  upon  the  sanitary  vent-flues  to 
properly  ventilate  these  rooms  by  drawing  the  odors  from  the  room 
through  the  sanitary  closets  and  urinals. 

Liberal  use  of  water  should  be  made  for  flushing  the  sanitary 
fixtures. 

The  janitor  should  be  in  the  building  in  the  morning  in  season 
to  have  the  building  properly  heated  and  the  ventilating  apparatus 
in  good  working  order  before  the  school  session  opens. 

After  cleaning  and  properly  starting  up  the  fires  he  should  open 
the  windows  admitting  fresh  air  to  the  cold-air  rooms  and  properly 
adjust  them  to  meet  the  existing  conditions  of  wind  and  outside 
temperature.  He  should  then  close  the  rotating  registers,  open 
the  vent  dampers  to  the  proper  degree  and  close  the  class-room 
doors. 


THE    SCHOOL   HOUSE.  113 

When  the  large  boilers  in  a  steam  heating  system  are  in  use  the 
steam  for  heating  the  vent-flues  should  be  supplied  from  that 
source ;  but  when  the  large  boilers  are  not  in  use,  or  with  a  furnace 
system  of  heating,  the  small  boiler,  usually  called  the  u  summer 
boiler,"  should  be  used. 

The  doors,  windows  and  transoms  should  be  kept  closed  while 
school  is  in  session  in  order  to  obtain  the  best  results  from  the 
heating  and  ventilating'  system,  and  to  secure  a  proper  circula- 
tion of  air  in  the  rooms. 

Springs  or  door-checks,  if  provided  on  all  outside  doors,  will 
soon  repay  the  extra  expense  by  the  saving  of  coal. 

Janitors  should  be  held  to  a  strict  accountability  that  the  heating, 
ventilating  and  sanitary  appliances  in  the  buildings  under  their  care 
are  managed  in  a  manner  to  secure  the  best  results. 

While  they  should  not  be  blamed  for  improperly  designed  or 
constructed  apparatus,  yet  they  should  be  required  to  secure  the 
best  possible  results  obtainable  from  the  apparatus  under  their 
control  and  to  keep  the  same  in  good  condition. 

The  janitor  should  see  that  the  boilers  or  furnaces  are  left  in 
proper  condition  at  the  end  of  the  school  term.  If  a  mechanical 
system  is  used  all  parts  of  it  should  also  be  attended  to.  If  any 
defects  develop  or  accidents  occur  to  the  boilers,  piping,  valves  or 
other  parts  of  a  steam-heating  system,  or  in  the  furnaces  or  stack- 
heaters  under  his  charge,  the  proper  authorities  should  at  once  be 
notified  in  order  that  the  required  repairs  may  be  made  promptly. 

All  accumulations  of  ashes  or  rubbish  should  be  promptly 
removed  from  the  building.  No  inflammable  or  combustible 
material  should  be  placed  or  allowed  to  accumulate  in  any  closet 
or  near  a  stairway  or  means  of  exit. 

Where  the  pupils  use  paper  instead  of  slates  for  their  work,  as 
is  now  generally  the  case  in  Massachusetts  schools,  care  should  be 
taken  that  it  be  promptly  burned  or  removed  from  the  building, 
and  not  allowed  to  accumulate  in  the  basement  or  in  any  closet. 

All  the  rooms  in  the  building  should  be  thoroughly  and  frequently 
swept  and  dusted,  the  sanitary  rooms  and  fixtures  washed  and 
disinfectants  freely  used  if  required. 

Where  outside  sanitary  buildings  are  used  they  are  often  found 
to  be  in  a  very  bad  condition.  The  janitor  should  be  required  to 
inspect  all  the  rooms  and  outbuildings  under  his  charge  at  least 
once  a  day  and  should  be  held  responsible  for  their  cleanliness. 
He  should  investigate  all  cases  of  misuse  of  the  sanitaries  and 
report  to  the  principal  of  the  school  or  the  school  committee. 


114  THE    SCHOOL   HOUSE. 

The  playgrounds  or  yards  should  be  kept  in  a  neat  condition  and 
not  become  the  repository  of  rubbish  of  any  kind.  In  winter  the 
janitor  should  see  that  all  walks  and  entrances  are  properly  freed 
from  snow  and  ice,  and  that  the  basement  doors  are  opened  a 
reasonable  time  before  commencement  of  the  school  session. 

The  average  annual  amount  of  coal  burned  in  well-heated  and 
ventilated  school  buildings  in  Massachusetts  is  about  ten  tons  per 
class-room.  This  includes  the  basement,  corridors  and  small  rooms 
in  an  ordinary  schoolhouse. 

Where  much  in  excess  of  this  amount  is  used,  unless  in  a  build- 
ing in  a  very  exposed  location,  or  one  badly  constructed,  or  where 
the  system  of  heating  and  ventilation  is  badly  designed,  it  is  fair  to 
presume  that  the  janitor  has  not  been  careful  in  managing  the 
fires. 

Where,  as  is  sometimes  claimed,  only  seven  or  eight  tons  of 
coal  are  burned  per  year,  it  will  be  found  that  the  air  supply  has 
been  restricted  to  an  amount  below  what  is  required  for  good 
ventilation. 

Some  janitors,  either  to  make  less  work  for  themselves,  or  to 
establish  a  record  for  economy  in  fuel,  shut  off  the  fresh-air  supply, 
or  fail  to  maintain  proper  heat  in  the  vent-flue  heaters. 

In  cities  and  large  towns  much  better  janitor  service  would  be 
obtained  if  a  competent  "head  janitor"  was  employed  and  if  it 
was  made  a  part  of  his  duty  to  see  that  the  other  janitors  were  fully 
instructed  in  and  properly  performed  their  duties. 

It  is  false  economy  to  employ,  as  is  often  done,  an  incompetent 
or  lazy  janitor  because  he  cafc  be  hired  cheap. 

It  is  not  advisable  that  one  janitor  should  have  charge  of  several 
buildings,  sometimes  situated  at  a  considerable  distance  from  each 
other. 

Very  frequently  janitors  do  not  receive  suitable  compensation  for 
their  work.  This  is  more  often  the  case  in  small  towns  than  in 
cities.  Fair  compensation  should  be  given  for  intelligent  and  faith- 
ful service. 

The  following  extracts  from  a  paper  read  at  the  twelfth  annual 
convention  of  the  International  Convention  of  Factory  Inspectors 
at  Boston  in  1898,  by  Thomas  Hawley,  State  Inspector  of  Boilers 
and  Examiner  of  Engineers  and  Firemen,  contain  many  facts  which 
it  would  be  advisable  for  school  committees,  superintendents  and 
principals  of  schools  to  carefully  consider  : 

"  There  is  another  class  of  boiler  that  has  received  considerable  attention 
from  the  department ;  namely,  those  in  schoolhouses  and  public  buildings. 


THE    SCHOOL    HOUSE.  115 

While  a  very  large  number  of  firms  and  manufacturers  have  sadly  neglected 
their  boilers  and  allowed  them  to  go  without  inspection,  those  who  control 
the  steam  plants  of  large  heating  plants  seem  to  have  been  more  guilty  in 
this  respect  Very  few  school  boilers  have  been  found  upon  which  it  was 
not  necessary  to  order  extensive  changes  to  make  them  safe  to  be  run.  In 
some  cities  many  of  the  boilers  have  been  punctured  with  a  blow  from  the 
light  hammer  each  inspector  uses.  It  has  been  the  policy  of  the  department 
to  have  the  changes  made  and  the  boilers  replaced  or  made  safe  without  let- 
ting the  facts  be  publicly  known  because  of  the  possible  alarming  of  parents, 
and  very  many  boilers  have  thus  been  repaired  without  the  pupils  or  parents 
knowing  or  suspecting  that  they  had  been  near  a  dangerous  boiler.  The 
reason  for  this  neglect  seems  difficult  to  understand.  It  may  arise  from  the 
fact  that  in  very  many  places  the  condition  of  the  boilers  is  cared  for  by  the 
public  buildings  department  or  committee  of  the  city  or  town,  and  the  boilers 
operated  and  under  the  care  during  the  year  of  janitors  appointed  by  the 
school  committee.  Each  tries  to  put  as  much  of  the  work  as  possible 
upon  the  other,  or  at  least  such  would  seem  to  be  the  case.  I  have  found 
boilers  in  schools  full  of  mud  and  deposits  up  to  the  hand  holes,  barrel 
staves,  and  bricks,  tubes  nearly  filled  up  with  soot,  and  back  connections 
filled  clear  to  the  boiler  with  soot  and  ashes,  hand-hole  plates  in  the  boiler 
rusted  solid  so  they  had  to  be  broken  off,  showing  the  boilers  had  neither 
been  opened  for  inspection  nor  cleaned  for  years.  The  janitors  claim  it  is 
the  work  of  the  building  department,  and  that  department  claims  that  if  they 
give  the  school  committee  a  good  boiler  and  that  committee  provides  the  man 
to  run  it,  that  man  should  see  it  was  run  properly,  and  properly  cared  for  and 
cleaned.  Between  the  two,  however,  the  boiler  is  not  long  in  getting  into 
dangerous  shape  ;  and  it  has  been  necessary  to  condemn  school  boilers  entirely 
in  some  cases  only  after  a  few  years'  use.  I  have  further  found  this  condition 
to  continue  even  after  the  inspector's  first  inspection,  when  the  boiler  comes 
to  be  again  inspected,  and  it  is  the  rule  almost  rather  than  the  exception  to 
find  schoolhouse  boilers  in  a  dirty  uncared-for  condition,  that  shortens  their 
lives,  develops  many  defects,  and  in  a  filthy  condition  unfit  for  a  proper  inspec- 
tion. The  matter,  in  fact,  it  seems  to  me,  has  been  complicated  in  one  way,  by 
the  inspector  making  a  third  person  upon  whom  the  others  rely,  and  they  will 
now  get  only  such  attention  as  the  inspector  can  give  in  his  annual  visit.  It 
appears  that  there  is  claimed  to  be  objections  to  having  the  boilers  operated  by 
persons  not  in  the  employ  of  the  building  department,  it  being  claimed  that  all 
employees  in  schools  should  be  controlled  by  the  school  committee.  Of  the 
merits  of  that  contention  I  know  nothing,  but  it  does  seem  as  though  the  two 
together  could  arrange  that  the  boiler  should  have  proper  care  and  attention, 
or  such  an  important  and  dangerous  part  of  the  school  equipment  as  the 
boiler  is  should  be  under  the  responsibility  of  the  school  committee.  Prior 
to  the  enactment  of  this  law,  boilers  have  exploded  in  schools  in  this  State 
with  disastrous  results  and  in  spite  of  the  poor  care  they  usually  obtain,  the 
regular  inspection  now  made  does  provide  a  material  safeguard. 

"  In  other  instances,  too,  heating  boilers  are  found  much  neglected.  The 
claim  is  made  that  they  are  run  at  such  low  pressure  that  they  cannot  explode. 
Yet  I  have  pieces  and  sections  of  these  boilers  in  my  possession  that  have 
exploded  and  very  recently,  and  with  disastrous  results.  Many  of  these  sec- 
tional boilers  are  of  cast  iron,  and  are  bad  in  design,  cheap  in  material,  and 


116  THE   SCHOOL   HOUSE. 

improperly  set  up  and  inadequately  fitted  with  safety  appliances.  They 
have  been  found  with  devices  that  bore  the  name  of  "safety-valve,"  but  were 
safety-valves  in  name  only.  This  most  important  fitting  on  a  boiler  is  very 
frequently  found  altogether  inadequate  in  size  and  in  unfit  condition.  I  have 
within  a  month  taken  safety-valves  from  school  boilers  which  were  stuck  so 
solid  they  could  not  be  moved  with  a  hammer,  and  had  become  so  by  neglect 
since  the  previous  inspection." 

The  following  rules  for  janitors  and  firemen  having  charge  of 
low-pressure  steam-heating  boilers  are  the  requirements  of  the 
Hartford  Steam  Boiler  Inspection  and  Insurance  Company. 

1.     GETTING  READY  TO  START. 

The  attendant  should  see  that  all  joints  are  properly  packed,  and  that  none 
leak  on  filling  the  boiler  with  water.  The  gauge  cocks,  water  gauge,  and 
safety  valve  should  be  carefully  examined  that  all  are  free  and  in  good  order. 
All  valves  in  piping  and  radiators  and  air  valves,  should  be  examined  and 
seen  to  be  in  order,  and  that  all  necessary  packing  or  repairs  have  been  done. 

2.     CONDITION  OF  WATER. 

The  first  duty  of  an  engineer  when  he  enters  his  boiler-room  in  the  morn- 
ing is  to  ascertain  how  many  gauges  of  water  there  are  in  his  boilers.  Never 
unbank  or  replenish  the  fires  until  this  is  done.  Accidents  have  occurred 
and  many  boilers  ruined  from  neglect  of  this  precaution. 

3.     RAISING  STEAM  AND  MANAGEMENT  OF  VALVES. 

All  steam  and  return-pipes  should  be  closed  before  fires  are  started.  When 
steam  has  been  raised  to  working  pressure,  the  steam  valves  should  be  opened 
very  slowlv.  After  the  boiler  pressure  is  established  in  the  pipes  the  return 
valves  can  be  opened,  allowing  the  water  of  condensation  to  flow  back  to  the 
boiler.  Whenever  necessary  to  shut  off  at  the  boiler  or  any  section  of  heat- 
ing system,  the  return  or  drip  valves  should  be  closed  first  and  then  the  steam 
valves.  In  letting  on  the  steam  the  supply  or  steam  valves  should  be  first 
opened  and  then  the  return  or  drip  valves.  This  caution  is  important. 

4.     Low  WATER. 

In  case  of  low  water,  immediately  cover  the  fires  with  ashes,  or  if  no  ashes 
are  at  hand,  use  fresh  coal,  and  shut  the  ash  pit  and  open  the  fire  doors.  Do 
not  turn  on  the  feed  under  any  circumstances  or  tamper  with  or  open  the 
safety  valves.  Let  the  steam  outlets  remain  as  they  are. 

5.     FEEDING. 

When  necessary  to  take  fresh  water  the  boiler  should  be  fed  as  slowly  as 
possible  to  avoid  unnecessary  contraction  and  leakage  at  joints. 

6.     GAUGE  COCKS  AND  WATER  GAUGE. 

Keep  gauge  cocks  clean  and  in  constant  use.  Glass  guages  should  not  be 
relied  upon  altogether. 

7.     SAFETY  VALVES. 

Raise  the  safety  valves  cautiously  and  frequently,  as  they  are  liable  to 
become  fast  in  their  seats. 


THE    SCHOOL   HOUSE.  117 

8.  SAFETY  VALVE,  AUTOMATIC  REGULATOR,  AND  STEAM  GAUGE. 
Should  the  gauge  at  any  time  indicate  the  limit  of  pressure  to  which  the 
regulator  is  adjusted  without  its  controlling  the  draft,  the  regulator  should 
be  examined  and  disconnected  from  the  damper  or  draft  door.  If  the  regu- 
lator works  quickly  and  well  the  trouble  is  in  the  damper  or  draft  door,  and 
it  should  at  once  be  cleaned  and  made  to  work  freely.  Should  the  regulator 
fail  to  work,  or  work  very  slowly,  the  pipe  connection  to  the  boiler  is  choked 
and  should  be  cleaned.  See  that  pressure  gauge,  regulator,  and  safety  valve 
agree;  in  case  of  difference,  notify  the  company's  inspectors. 

9.     CLEAN  PLATES  AND  HEATING  SURFACES. 

Particular  attention  should  be  taken  to  keep  plates  and  parts  of  boilers 
exposed  to  the  fire  perfectly  clean.  Also,  all  tubes,  flues  and  connections 
well  swept.  This  is  particularly  necessary  in  many  types  of  small  heating 
boilers  with  large  heating  surfaces  and  small  heat  passages,  as  they  soon 
foul  if  neglected.  Strict  attention  to  this  rule  is  necessary  for  full  economy 
and  capacity  of  boilers. 

10.     BLOWING  OFF. 

If  necessary  to  blow  down  during  the  season,  the  fires  should  be  hauled 
and  furnaces  and  bridge  wall  cleaned  at  least  two  hours  before  blowing 
down.  Allow  the  boiler  to  stand  until  cool  before  filling  with  cold  water. 

11.     LAYING  UP  BOILERS  FOR  THE  SEASON. 

Haul  fires,  clean  furnaces,  and  run  off  the  water  while  hot.  Thoroughly 
clean  all  heating  surfaces  at  once.  Remove  hand  and  man-hole  plates,  dry 
out  water  if  any  remains,  and  leave  the  boiler  thoroughly  clean  and  dry. 
Drain  all  water  from  return  drip-pipes.  All  good  systems  are  provided  with 
drip-cocks  at  lowest  point  in  return  pipes  for  this  purpose.  During  the  sum- 
mer see  that  no  water  can  drip  or  moisture  collect  in  or  around  the  boiler. 

12.     PIPING,  RADIATORS,  AND  SETTINGS. 

Mark  all  joints  that  have  shown  signs  of  leakage  and  need  packing ;  also 
air-cocks  and  valves  and  anything  that  may  need  repairs  before  using  another 
season.  If  repairs  are  needed  to  boiler  settings  see  what  they  are  and  have 
them  made  while  the  boiler  is  idle. 

INSPECTORS  WILL  GIVE   SPECIAL  INSTRUCTIONS  IN  CASES  NOT  COVERED 

BY  THESE  RULES. 
83T  If  the  Boiler  shows  distress  or  unusttal  behavior  notify  the  Company  at  once. 

A    FEW    GENERAL    SUGGESTIONS    FOR     OPERATING    HEATING 
AND  VENTILATING  APPARATUS  IN  SCHOOL  BUILDINGS. 

Furnaces. 

Care  should  be  taken  not  to  have  too  deep  or  heavy  a  fire  in  the 
furnaces  during  Spring  and  Fall,  as  there  is  great  danger  of  over- 
heating the  school-rooms. 

During  cold  winter  weather  run  deep,  full  fires  in  the  furnaces 
with  coal  up  to  within  three  inches  of  the  top  of  the  fire-pot  at  the 
edges,  and  well  crowned  above  that  level  toward  the  middle. 


118  THE    SCHOOL    HOUSE. 

During  extreme  cold  weather  the  grate-bars  should  be  turned 
over  at  least  twice  each  day.  Ashes  should  not  be  allowed  to 
accumulate  in  the  ash-pits. 

Fresh-Air   Windows. 

The  fresh-air  windows  should  be  wide  open  daytimes  in  mild 
and  calm  weather,  and  never  less  than  one-quarter  open  even  in 
extreme  weather,  as  judicious  handling  of  the  school-room  vent- 
duct  dampers  should  prevent  the  passage  of  too  much  cold  air 
out  of  the  building,  thereby  checking  the  inflow  through  the 
furnace  chambers. 

Always  close  the  fresh-air  windows  tightly  nights,  Sundays  and 
vacations,  but  never  close  the  fresh-air  windows  entirely  when 
school  is  in  session. 

Controlling"   Temperature  of  School-rooms. 

The  temperature  of  the  air  entering  each  school-room  should 
be  regulated  by  the  teacher  occupying  the  room, — this  is  done 
by  pulling  the  warm-air  chain,  or  the  cold-air  chain,  as  the  needs 
of  the  moment  may  demand.  The  teacher  should  pull  the 
necessary  chain  but  a  little  way  at  a  time,  —  this  to  prevent  too 
sudden  a  rise  or  drop  in  the  temperature  of  the  air  entering  the 
school-room. 

Dampers  in    Ventilating  Ducts. 

The  outflow  of  air  from  eaqh  school-room  is  controlled  by  a 
damper,  which  should  be  adjusted  by  the  janitor  before  each 
session  of  school,  according  to  the  outside  conditions.  In  mild  and 
calm  weather,  this  damper  should  be  wide  open;  but  when  the 
weather  is  cold  and  windy,  it  should  be  partially  closed.  Never 
should  it  be  closed  entirely  when  school  is  in  session. 

During  extremely  windy  weather  the  vent-duct,  unless  controlled 
by  the  use  of  this  damper,  might  take  out  from  the  school-rooms  a 
larger  quantity  of  air  than  the  warm-air  ducts  could  provide  suffi- 
ciently heated, — the  excess  outflow  finding  its  way  into  the  school- 
room cold,  through  leakage  around  the  windows  and  doors  and 
through  the  walls. 

Intelligence  should  be  used  in  operating  these  vent-duct  dampers. 

Schoolroom   Windows  and  Doors. 

A  much  better  circulation  of  air  within  the  school-rooms  can  be 
obtained  if  the  windows  and  doors  of  the  school-rooms  be  kept 
closed.  Windows  and  doors  should  always  be  kept  closed  when 
the  large  furnaces  are  in  operation. 


THE    SCHOOL   HOUSE.  119 

If,  when  the  chains  which  allow  the  cool  air  to  enter  the  school- 
rooms are  pulled  way  down,  the  furnace  drafts  entirely  checked, 
and  it  is  still  found  that  the  school-rooms  are  uncomfortably  warm, 
doors  and  windows  may  then  be  opened  at  discretion  of  the 
teacher. 

Air  Rotation. 

At  the  close  of  school  at  night  the  fresh-air  windows  should  be 
tightly  closed  and  passage  of  air  out  from  the  building  through  the 
vent-ducts  entirely  checked  ;  the  rotating  dampers  which  allow  air 
from  the  school-rooms  to  pass  back  to  the  furnaces  should  then  be 
opened,  and  the  furnace  fires  fixed  for  the  night.  A  circulation  of 
air  within  the  building  will  thus  be  established,  and  a  reasonable 
temperature  maintained  in  the  school-rooms  during  the  night,  with 
the  minimum  consumption  of  fuel. 

Stack-Heater. 

When  the  weather  is  cold  enough  to  require  good  fires  in  the 
large  furnaces  which  heat  the  school-rooms,  these  furnaces  will 
often  furnish  enough  power  to  move  the  air  required ;  but,  on  the 
other  hand,  when  only  low  fires  are  needed  in  the  large  furnaces, 
it  may  be  necessary  to  run  the  stack -heater  in  order  to  move  the 
desired  volume  of  air  through  the  school-rooms. 

In  warm  or  muggy  weather,  a  good  fire  should  always  be  kept 
in  the  stack-heater,  not  only  for  the  ventilation  of  the  school-rooms, 
but  for  the  ventilation  of  the  sanitaries  as  well. 

With   Steam-Boiler  Auxiliary. 

The  steam  boiler  supplies  steam  for  the  radiators  in  the  corridors 
and  small  rooms,  and  also  furnishes  heat  for  the  vent-ducts. 

The  steam  may  be  supplied  to  the  radiators  in  the  corridors  and 
small  rooms  when  desired. 

In  warm  or  muggy  weather  the  vent-flue  radiators  should  always 
be  kept  hot,  in  order  to  secure  the  proper  ventilation  of  the 
school-rooms. 

Printed  instructions  (in  large  type)  as  above,  if  posted  where 
they  can  be  readily  seen  by  the  janitor,  will  be  of  great  service 
to  him  when  first  taking  charge  of  the  heating  and  ventilating 
apparatus  in  a  schoolhouse. 


CHAPTER    IX. 


SANITARIES. 

THE  sanitary  appliances  in  schoolhouses  should  receive 
careful  attention,  not  only  when  being  installed,  but 
also  from  the  janitor. 

For  buildings  of  large  size  the  sanitary  fixtures  are  generally 
placed  in  the  basement,  or,  what  would  be  better,  in  an  extension 
in  which  they  can  be  reached  from  the  class-room  floors  and  located 
where  they  can  be  properly  ventilated,  independently  of  the  other 
parts  of  the  building. 

On  account  of  the  cost  of  construction,  and  frequently  from  an 
architectural  point,  this  is  not  often  done,  and  part  of  the  basement 
is  utilized  for  that  purpose. 

Where  a  suitable  water  supply  is  available  and  the  fixtures  are 
of  good  construction  and  properly  placed  and  ventilated,  the  base- 
ment is  not  an  objectionable  place. 

Individual  closets  and  fixtures  are  preferable  to  those  known  as 
range  closets  or  latrines,  but  where  the  latter  are  properly  flushed 
and  vented  they  are  not  objectionable  and  are  frequently  used  on 
account  of  the  lower  cost.  With  individual  seat  bowls  those 
having  a  seat  vent  three  or  four  inches  diameter  are  to  be  preferred. 
The  individual  bowls  should  be  vented  into  a  pipe  increasing  in 
size  as  additional  vents  are  connected  and  leading  to  a  heated  vent- 
flue  or  one  where  a  fan  is  provided. 

In  large  and  the  best  class  of  school  buildings  fans  are  used,  but 
are  more  expensive  than  steam-heated  flues. 

The  partitions  between  the  closets  should  be  raised  on  metal 
supports  from  six  to  ten  inches  above  the  cement  floor  of  the 
basement  and  no  woodwork  on  or  around  the  bowls  should  be 
used,  except  such  as  is  required  for  the  seats.  This  allows  the 
janitor  to  use  a  hose  freely  and  prevents  the  accumulation  of  offen- 
sive matter  in  places  not  easily  reached. 

Each  bowl  should  be  provided  with  an  automatic  flushing  device, 
of  which  there  are  several  on  the  market  that  give  good  results. 
Apparatus  is  frequently  used  by  which  the  whole  number  of  bowls 
are  automatically  flushed  at  regular  intervals. 


THE    SCHOOL   HOUSE.  121 

When  range  closets  are  used  they  should  have  a  large  vent  and 
flush.  It  is  better  to  have  a  separate  vent  for  each  seat  and  to 
unite  the  several  vents  into  one  main  vent. 

Range  closets  should  not  be  incased  in  wood  on  the  sides  or 
ends,  and  the  full  width  between  the  partitions  should  be  hinged  in 
order  that  the  whole  length  of  the  range  can  be  thoroughly  cleaned. 

The  waste-pipe  should  be  of  ample  size  but  not  too  large  to 
prevent  thorough  flushing. 

For  the  main  pipe  six  inches  is  a  good  size.  Extra  heavy  iron 
pipe  within  the  building  is  to  be  preferred  to  vitrified  tile  pipe,  on 
account  of  the  liability  of  tile  pipe  to  become  separated  at  the 
joints  and  allow  leakage  into  the  ground  under  the  basement  floor. 
The  iron  pipe  should  extend  well  beyond  the  foundation  wall  and 
in  all  cases  should  be  well  trapped  and  provided  with  suitable 
clean-outs. 

The  writer  has  seen  tile  pipes  that  had  been  improperly  connected 
or  not  made  water-tight  that  had  leaked  so  badly  as  to  saturate  the 
ground  for  a  considerable  distance,  and  where  it  has  been  found 
necessary  to  take  up  the  floor  and  remove  a  considerable  quantity 
of  earth,  replace  it  with  fresh  and  substitute  iron  pipe.  Where 
cremating  closets  have  been  used  the  saturation  of  the  earth  has 
been  more  noticeable  than  with  water-flushed  fixtures. 

Where  there  was  no  available  water  supply  for  flushing  closets 
cremating  closets  have  been  used,  and  where  the  vaults  were  con- 
structed of  brick  laid  in  and  covered  with  Portland  cement  and  a 
good  drain  provided  to  remove  the  liquid  matter,  and  where  ample 
ventilation  into  a  heated  flue  was  provided,  they  have  not  been 
objectionable  if  properly  cared  for  by  the  janitor.  Odors  were  not 
perceived  in  the  building,  but  complaints  have  been  made  by  per- 
sons residing  near  the  buildings  when  the  closets  were  burned  out. 

Where  a  water  supply  can  be  had  it  is  better  to  use  flushing 
closets. 

Where  a  water  supply  is  available,  but  no  system  of  sewers, 
flushing  closets  or  range  closets  can  be  used  by  constructing  a 
double  cesspool ;  that  is,  two  cesspools  located  at  such  a  distance 
from  the  building  that  there  is  no  danger  of  the  leakage  finding  a 
way  under  the  building  —  one  cesspool  to  receive  the  waste-pipe 
from  the  sanitary  fixtures  and  to  allow  the  heavier  and  more  solid 
matter  to  settle,  the  other  to  be  constructed  of  brick  or  field  stone 
to  allow  the  liquid  to  filter  off. 

The  two  cesspools  are  connected  by  a  siphon  pipe  (six  inches  in 
diameter),  which  will,  when  the  first  receptacle  has  become  partly 


122  THE    SCHOOL   HOUSE. 

filled  with  liquid,  transfer  it  to  the  second  or  filtering  cesspool. 
This  arrangement  cannot  well  be  used  where  the  ground  is  con- 
stantly wet  or  where  water  in  the  ground  is  much  above  the  bottom 
of  the  cesspool,  or  in  clay. 

Each  cesspool  should  be  provided  with  a  perforated  manhole 
cover  to  prevent  an  accumulated  gas  from  forcing  its  way  through 
the  trap  and  entering  the  schoolhouse  basement. 

The  urinals  in  a  schoolhouse  basement,  where  individual  fixtures 
are  not  used,  should  be  of  slate,  and  should  have  suitable  divisions 
for  the  older  grades  of  pupils.  In  many  school  buildings  the  divisions 
are  omitted  on  account  of  the  additional  cost  of  construction. 

A  urinal  has  been  constructed  for  an  eight-room  school  building 
in  accordance  with  the  following  specifications,  and  used  with 
satisfactory  results : 

"A  gutter  slab,  8  feet  long  and  18  inches  wide  and  3J  inches 
thick,  in  one  piece ;  one  floor  slab  8  feet  long,  2  feet  6  inches  wide 
and  1J  inches  thick,  sloped  to  the  gutter  slab ;  two  end  slabs  5  feet 
high,  2  feet  6  inches  wide  and  1  inch  thick,  and  two  back  slabs 
each  4  feet  long,  5  feet  high  and  1  inch  thick,  making  the  urinal 
when  completed  8  feet  long,  5  feet  high  and  3  feet  3f  inches  wide , 
including  the  floor  slab.  The  gutter  is  to  be  countersunk  2£  inches 
deep  at  the  outlet  and  1  inch  deep  at  the  summit ;  the  back  slants 
5  inches  and  is  to  be  grooved  f-inch  into  ends,  and  all  are  to  be 
grooved  J-inch  into  the  gutter  slab ;  all  to  be  strongly  clamped 
together  and  bolted  to  the  brickwork,  using  brass  clamps  and  brass 
expansion-bolts.  The  floor  slab  laps  3J  inches  on  the  gutter  and 
is  closely  fitted  to  the  ends ;  the  outer  or  waste-pipe  is  a  brass 
cesspool,  having  3-inch  waste  trapped. 

UA  J-inch  brass  flush-pipe  runs  the  entire  length,  placed  within 
two  inches  of  the  top,  and  perforated  so  as  to  give  a  uniform  and 
even  flush;  this  will  have  a  controlling  valve. 

u  The  end  slab  near  the  outlet  has  an  8  by  10  inches  opening  to 
receive  an  8  by  10  uptake  vent-pipe  and  an  8  by  8-inch  ventilating- 
hood  which  runs  on  top  of  the  back  slab  the  entire  length.  This 
connects  with  an  8  by  8-inch  uptake  vent-pipe,  both  of  these 
uptake  pipes  and  hood  being  made  of  heavy  galvanized  iron, 
properly  secured  in  place.  The  uptake  pipes  are  connected  near 
the  ceiling  with  the  vent-duct  leading  to  the  heated  brick  vent-flue. 
All  exposed  parts  of  the  slate  are  to  be  planed,  rubbed  smooth  and 
well-oiled,  the  joints  filled  with  slate  cement  in  the  best  manner." 

A  better  arrangement  is  that  of  a  slate  urinal  vented  at  the 
bottom  of  the  front  slab  (having  at  least  12  square  inches  of 


THE    SCHOOL    HOUSE.  123 

opening  for  each  16  inches  length)  into  a  space  between  the  front 
inclined  slab  and  a  perpendicular  back  slab,  the  space  at  the  top  to 
be  at  least  four  inches  wide  and  the  full  length  -of  the  slabs  and 
covered  on  the  ends  and  top  by  slate  slabs,  except  where  it  is 
vented  near  the  center  of  the  top  by  a  galvanized-iron  vent-pipe 
four  inches  wide  and  at  least  20  inches  long,  which  changes  its  form 
into  a  10  inches  diameter  round  pipe  connected  with  a  heated 
brick  flue. 

The  perpendicular  back  slab  is  grooved  J-inch  into  the  gutter 
slab.  Tke  inclined  front  slab  at  the  bottom  projects  over  the 
gutter  at  least  three  inches. 

The  Boston  Board  of  Schoolhouse  Commissioners  recommend, 
for  water-closets  and  urinals,  44  Ventilation  through  fixtures,  back 
of  urinals,  and  13  square  inches  local  vent  in  water-closets. 

44  Water-closets.  The  basement  water-closets  for  primary  and 
certain  grammar  schools  are,  approved  washout  vitreous  earthen- 
war*e  or  enamel  iron  latrines,  or  short  hopper  closets;  elsewhere  a 
heavy  wash-down  closet,  all  as  specified  by  the  Commissioners, 
13  square  inches  local  vent  from  each  section  of  closet,  automatic 
flush. 

44  Slate  partitions  for  latrines  resting  on  top  of  range,  5  feet 
6  inches  high  and  about  4  feet  wide ;  for  closets  8  inches  above 
floor,  5  feet  6  inches  by  6  feet  high  and  4  feet  wide ;  in  both  cases 
supported  at  ends  with  iron  pipe  from  floor  to  ceiling.  No  doors. 
(These  may  be  added  later.) 

4 'Urinals.  The  urinals  will  be  of  slate,  floor  slab  and  trough, 
the  back  4  feet  6  inches  high,  without  partitions,  flushed  auto- 
matically with  J-inch  perforated  pipe,  vented  at  bottom  (opening 
10  square  inches  for  each  16  inches  length)  into  space  behind 
back. 

44  Piping.  Cast-iron  must  be  in  trenches  in  basement,  running 
trap  with  direct  indirect  fresh-air  inlets,  clean-outs  at  every  change 
of  direction ;  soils  and  vents  exposed  as  far  as  possible,  no 
asphaltum,  but  oil-tested  red  lead  and  three  coats  paint. 

44  Supplies  exposed  as  far  as  possible  ;  where  covered  may  be  lead, 
elsewhere  brass,  no  nickel  plated.  Hot-water  for  janitor's  use  in 
basement,  and,  if  convenient,  for  master's  and  teachers'  toilets. 
Supply  from  boiler,  and  from  summer  boiler,  if  any,  or  from  a 
gas-heater." 

All  plumbing  should  be  carefully  tested  to  ascertain  if  it  is  tight 
and  well  trapped,  especially  where  smaller  pipes  enter  the  main 
drain. 


124  THE    SCHOOL   HOUSE. 

Where  water-closets  are  provided  in  teachers'  toilet  rooms  they 
should  be  well  vented. 

Soapstone  sinks  are  frequently  used  in  the  basement  in  place  of 
the  ordinary  cast-iron  ones.  Enameled  iron  is  sometimes  used. 

Many  school  buildings  have  stream  drinking  founts  instead  of 
faucets  and  dippers. 

Outside  Sanitary  Buildings. 

The  care  of  sanitary  buildings  in  many  towns  and  villages  is  a 
matter  that  is  often  neglected,  and  frequently  they  are  fotind  in  a 
condition  that  does  not  bring  credit  to  those  who  have  the  imme- 
diate care  of  such  buildings. 

This  is  something  to  which  school  boards  and  teachers  should 
give  more  attention  than  they  usually  do.  They  should  see  that 
such  places  are  kept  in  at  least  a  decent  condition  and  that  the 
vaults  are  properly  cleaned. 

The  janitor  should  be  required  to  visit  the  sanitary  building 
daily,  cover  the  contents  of  the  vault  with  fresh  earth  or  ashes,  and 
see  that  the  seats,  urinals  and  floors  are  in  good  condition. 

In  winter  especially  these  buildings  are  often  found  in  bad  condi- 
tion, as  there  is  seldom  any  provision  for  heating.  While  a  stove 
in  such  buildings  would  add  much  to  the  comfort  of  the  pupils, 
practically  it  would  be  of  little  use,  as  the  fire  would  not  be  properly 
tended  by  the  ordinary  janitor,  and  some  committees  would  object 
to  what  they  would  call  a  needless  waste  of  fuel. 

Where  outside  privies  are  used  they  should  be  placed  at  such  a 
distance  from  the  schoolhouse  that  odors  will  not  reach  the  class- 
rooms when  the  wind  is  blowing  from  the  direction  of  the  sanitary 
building.  When  practicable  they  should  not  be  located  in  a  direc- 
tion from  which  the  prevailing  winds  blow. 

Particular  care  should  be  taken  that  they  are  not  located  near  the 
fresh-air  supply  for  the  furnaces  or  indirect  radiators  in  the  school 
building. 

When  such  buildings  are  used  it  is  advisable  to  provide  a  tight 
vault  with  the  walls  laid  in  cement  and  covered  on  the  inside  and 
bottom  with  cement. 

A  vault  three  or  four  feet  deep  and  from  four  to  five  feet  wide, 
extending  the  length  of  the  building,  will  be  found  of  ample  size 
if  cleaned  out  as  often  as  it  should  be. 

The  walls  should  be  not  less  than  12  inches  thick  (some  are  16), 
and  the  bottom  of  cement  not  less  than  two  inches  thick  if  the 
ground  is  solid,  but  if  the  building  is  placed  where  the  ground  is 


.  THE    SCHOOL   HOUSE.  125 

wet  or  not  firm,  there  should  be  below  the  cement  a  layer  of  con- 
crete not  less  than  four  inches  thick. 

The  vault  should  extend  beyond  the  rear  of  the  building  and  be 
covered  with  inclined  and  hinged  doors  for  removing  the  contents. 
On  the  rear  of  the  building,  and  extending  not  less  than  two  feet^ 
above  the   ridge,  should  be  a  ventilating   shaft  leading  from   the 
vault. 

The  windows  should  be  hinged  and  fitted  with  attachments  for 
readily  opening  and  closing. 

Locks  should  be  placed  on  the  doors  for  closing  the  building 
when  the  schoolhouse  is  not  occupied. 

Where  the  ordinary  trough  urinal  is  used  it  should  be  well 
covered  with  sheet  zinc  and  the  floor  under  and  at  least  three  feet 
in  front  should  be  covered  with  sheet  zinc  and  the  joints  made 
water-tight. 

Hinged  self-closing  covers  should  be  furnished  for  the  seats. 

Where  it  is  not  practicable  to  provide  separate  buildings  for  boys 
and  girls,  one  with  a  partition  may  be  used,  and  a  board  division 
fence  or  divided  covered  way  leading  from  the  schoolhouse  to  the 
building. 

Where  the  sanitary  building  is  attached  to  the  schoolhouse  by  a 
covered  way  (which  is  not  always  advisable),  self-closing  doors 
should  be  provided  at  each  end  and  ample  provision  made  for 
doors  or  louvres  in  the  sides  to  prevent  odors  entering  the  school 
house. 

Brick  piers  are  sometimes  placed  in  the  vault  under  the  rear 
wall  of  the  building  if  it  is  of  considerable  length.  Three-inch 
iron  pipe  is  preferable  to  the  brick  piers,  as  the  vaults  can  be  more 
readily  cleaned  when  this  is  used. 

Whatever  class  of  sanitary  fixtures  or  buildings  are  provided  for 
schoolhouses  it  is  requisite  that  constant  supervision  should  be 
exercised  by  teachers  and  janitors  to  have  them  kept  in  good  con- 
dition. It  should  be  a  teacher's  duty  to  see  that  the  janitor  faith- 
fully attends  to  that  part  of  his  work. 

In  many  sanitary  buildings,  especially  in  the  smaller  towns,  the 
writer  has  found  conditions  that  should  not  be  tolerated  and  would 
not  have  been  allowed  to  exist  if  either  the  school  committee  or 
teachers  had  taken  means  to  ascertain  whether  the  janitor  was 
attending  to  this  part  of  his  duty. 

Vaults  were  found  that  apparently  had  not  been  cleaned  out  for 
years,  seats  and  floors  covered  with  filth,  obscene  writing  on  the 
walls,  and  doors  with  hinges  and  fastenings  broken. 


126  THE    SCHOOL   HOUSE. 

It  has  frequently  been  necessary  to  order  seats  and  floors  removed 
and  new  ones  substituted  in  outside  buildings,  and  in  some  cases 
new  buildings  were  built. 

Such  unsanitary  conditions  are  demoralizing,  and  if  parents  had 
known  of  the  existing  conditions  there  would  have  been  strong 
protests  entered  with  the  school  committee. 

Where  a  supply  of  fresh  earth  has  not  been  obtained,  kept  dry 
and  free  from ,  freezing,  in  cold  weather  sifted  ashes  from  the 
furnaces  or  boilers  can  be  used  to  good  advantage  in  the  vaults. 

In  some  badly-constructed  cremating  closets  and  in  some  of  the 
so-called  u  foul  air  gathering  rooms"  with  poorly  cemented  floors, 
trouble  has  been  caused  by  the  breaking,  scaling  or  cracking  of  the 
cement,  which  allowed  the  liquid  matter  to  soak  into  the  ground 
under  the  basement  floor  and  extensive  repairs  and  alterations  were 
required.  Where  any  class  of  cremating  closets  are  used  in  school - 
houses,  extra  care  should  be  taken  that  the  vaults  are  made  per- 
fectly water-tight,  thoroughly  built  and  well  drained. 

The  heat  in  sanitary  vent-shafts  or  ducts  should  be  maintained 
at  all  times  during  the  school  term,  except,  perhaps,  when  there  is 
a  very  considerable  difference  between  the  temperature  in  and  out- 
side the  building,  or  when  a  very  strong  wind  is  blowing  across 
the  top  of  the  shaft  and  causing  an  outward  flow  of  air. 

The  sanitary  vent-flue  should  never  be  placed  in  a  position  in 
which  back  drafts  may  be  caused  by  the  wind  being  deflected  by 
roofs,  towers  or  other  projections. 

When  a  contagious  disease  appears  among  the  pupils  the  entire 
schoolhouse  should  at  once  be  thoroughly  fumigated  and  disinfected 
under  the  direction  of  a  competent  person. 


PART    II 


Plans  and  Descriptions 


OF 


School  Houses 


i  DDDDDJDDD 

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i  D  D  D  D  aD  D  D 


_ 
i  D  ODD  "Bib  DO 


PLANS   AND    DESCRIPTIONS 

OF   SCHOOL   HOUSES. 


PLAN  of  a  one-story,  one-room  schoolhouse  with  sections 
of  heating  and  ventilating  apparatus.  The  school-room 
is  28  by  32  feet  and  12  feet  high,  with  seats  for  48  pupils. 
In  front  are  two  clothing  rooms,  one  for  boys  and  one  for  girls. 
A  cast-iron  sink  is  provided  in  each.  There  is  a  closet  opening 
from  the  school-room  for  the  teacher.  Between  the  clothing-rooms 
are  the  furnace-room  and  fuel-bin. 

The  heating  is  by  a  medium-sized  portable  furnace.  Fresh  air 
is  taken  in  through  a  galvanized-iron  duct  under  the  floor.  This 
duct  is  48  by  16  inches  where  it  passes  through  the  underpinning, 
and  the  bottom  is  slightly  inclined  toward  the  outside  to  allow  rain 
that  may  be  driven  in  to  run  out.  The  inlet  is  protected  by  a  wire 
grill  of  one-eighth-inch  wire  set  in  a  channel-iron  frame. 

A  valve,  with  a  pulley  and  a  chain  passing  up  into  the  furnace 
room,  is  provided,  with  a  suitable  catch  to  hold  the  valve  in  any 
desired  position  when  a  strong  wind  is  blowing,  or  when  the 
damper  is  closed  at  night.  Before  reaching  the  furnace  the  duct  is 
tapped  by  a  perpendicular  one  24  by  30  inches,  to  furnish  cold  air 
for  mixing  with  the  warm  air  from  the  furnace  when  it  is  desired 
to  reduce  the  temperature  and  yet  supply  fresh  air  to  the 
school-room. 

A  mixing-valve  with  pulleys  and  chain  leading  to  the  school- 
room is  provided  to  enable  the  teacher  to  regulate  the  temperature. 
A  suitable  catch  (as  shown  in  another  plate)  is  provided  to  hold 
the  chain  and  damper  in  any  desired  position. 

Warm  air  enters  the  school-room  through  an  opening  30  by  30 
inches,  covered  with  a  wire  grill  of  one-eighth  inch  wire,  one-and- 
one-half-inch  diamond  mesh,  set  in  a  channel-iron  frame.  The 
bottom  of  this  opening  is  eight  feet  above  the  floor.  The  warm 
air  is  thrown  forward  across  the  ceiling,  spreading  till  it  reaches 
the  three  outer  or  cold  sides,  where  it  is  cooled  and  falls,  and  is 
drawn  back  across  the  lower  part  of  the  room  and  removed  by  the 
exhaust  vent  stack. 

NOTE. —  The  method  of  setting  up  this  heating  apparatus  was  designed  by  the  writer 
and  has  given  satisfactory  results  where  used. 


130  THE    SCHOOL    HOUSE. 

In  the  top  of  the  cold-air  duct,  before  it  reaches  the  upright  part, 
is  a  trap-door  covered  on  the  bottom  with  galvanized  iron  which 
opens  up  into  the  furnace  room.  This  is  for  rotating  the  air  within 
the  building  at  night  or  when  the  school-room  is  not  occupied. 
By  closing  the  outer  damper  in  the  fresh-air  duct,  closing  the  vent 
shaft  opening  from  the  school-room,  and  opening  the  doors  between 
the  school-room  and  furnace-room,  the  air  is  rotated  through  the 
furnace  and  a  considerable  saving  of  fuel  is  made.  This  trap-door 
should  never  be  opened  when  the  school-room  is  occupied. 

The  exhaust  vent  or  foul-air  shaft  has  four-inch  brick  walls,  and 
is  30  by  24  inches  inside.  Adjoining,  and  in  the  same  stack,  are 
the  smoke  flues  for  the  furnace  and  vent-shaft  heater. 

A  small  stove  or  u  stack-heater,"  supported  on  two  iron  bars,  is 
placed  in  the  vent  shaft  just  above  the  foul-air  entrance. 

The  foul-air  vent  opening  is  24  by  30  inches,  and  the  bottom  is 
at  the  level  of  the  floor,  being  covered  with  a  wire  grill  similar  to 
that  at  the  warm-air  inlet. 

A  curved  galvanized-iron  damper  is  placed  in  the  opening  to 
regulate  the  outflow  of  air  as  may  be  desired  on  account  of  outside 
temperature  or  wind,  or  to  close  at  night  or  when  the  school-room 
is  not  in  use. 

Plates  Nos.  II  and  III  show  plan  and  sections  of  what  is 
known  as  the  portable  schoolhouse  —  a  one-room  school  building 
for  temporary  use  where  the  larger  buildings  are  overcrowded,  or 
for  use  until  better  accommodation  can  be  provided. 

The  building  is  constructed  of  light  timbers  and  covered  with 
matched  and  battened  boards.  The  roof  boards  are  covered  with 
canvas,  painted  three  coats. 

The  building  is  supported  on  cedar  posts  and  the  space  between 
the  floor  and  the  ground  is  inclosed  with  two  thicknesses  of  matched 
boards,  the  outside  boarding  being  perpendicular  and  the  inside 
placed  horizontally.  The  inside  of  the  building  is  sheathed  on  the 
sides,  ends  and  ceiling  with  matched  boards.  Between  the  upper 
and  lower  floor  boards  are  two  thicknesses  of  heavy  building  paper. 

The  heating  is  by  a  jacketed  stove  or  small  portable  furnace, 
which  receives  the  air  to  be  heated  and  for  ventilation  through  a 
galvanized-iron  duct  leading  from  under  the  front  platform,  which 
is  not  boarded  on  the  end,  but  provided  with  open  lattice- work. 
A  damper  is  provided  in  this  fresh-air  duct  by  which  the  quantity 
of  air  to  be  heated  is  regulated  according  to  the  temperature  of  the 

NOTE.  — The  method  of  setting  up  this  heating  apparatus  was  designed  by  the  writer 
and  has  given  good  results. 


THE   SCHOOL   HOUSE. 


131 


SECTION  THROUG 
VENT     SHAFT 


182 


THE   SCHOOL   HOUSE. 


ZB 


THE   SCHOOL   HOUSE.  133 

outside  air  or  the  force  of  the  wind.  This  damper  is  operated  by 
a  pulley  and  a  chain  passing  up  into  the  school-room. 

The  air  passes  up  between  the  casing  and  the  stove  and  is  intro- 
duced into  the  school-room  through  a  curved  top,  which  changes 
the  direction  of  the  current  and  throws  the  air  across  the  ceiling  to 
the  coldest  part  of  the  room.  This  curved  top  is  movable^  and 
can  be  changed  to  throw  the  air  against  the  direction  of  the  prevail- 
ing wind  when  desirable,  thereby  securing  a  more  even  distribution 
of  heat  in  the  schoolroom. 

In  the  floor  of  the  schoolroom  and  behind  the  jacketed  stove  is  a 
trap-door  opening  into  the  fresh-air  duct.  By  closing  the  outer 
damper  in  the  fresh-air  duct,  opening  the  trap-door  and  closing  the 
damper  at  the  opening  into  the  ventilating  shaft,  the  air  can  be 
rotated  through  the  building  at  night.  This  also  enables  the  janitor 
to  quickly  warm  the  room  in  the  morning  before  the  school  session 
begins.  The  trap-door  should  never  be  opened  while  the  school  is 
in  session. 

The  ventilation  is  by  means  of  a  galvanized-iron  shaft  in  which 
is  placed  a  small  stove  or  u  stack-heater"  just  above  the  top  of  the 
vent  opening,  the  bottom  of  which  opening  is  at  the  floor  level. 

The  stack-heater 'is  supported  on  two  iron  bars  and  the  lower 
part  of  the  ventilating  shaft  from  the  floor  to  above  the  heater  is 
provided  with  a  double  casing,  filled  with  an  non-heat-conducting 
material,  preferably  asbestos.  This  vent  opening  is  covered  by  a 
detachable  wire  grill. 

At  the  vent  opening  is  placed  a  curved  galvanized-iron  damper, 
operated  by  a  chain  and  catch. 

The  smoke  from  the  jacketed  stove  and  from  the  stack-heater 
enters  a  galvanized-iron  smoke-pipe  which  passes  up  near  the 
center  of  the  vent-shaft  and  above  a  galvanized-iron  hood  or  cap 
above  the  top  of  the  shaft. 

The  outer  clothing  of  the  pupils  is  to  be  hung  on  hooks  in  the 
porch  clothing  room,  which  is  ventilated  into  the  vent-shaft  through 
a  10  by  12  inch  register  at  the  floor  level,  having  valves. 

The  vent-shaft  is  24  by  30  inches,  inside  measurement.  The 
opening  from  the  school-room  is  30  inches  long  by  24  inches  high. 

The  galvanized-iron  fresh-air  duct  is  36  by  16  inches,  and  the 
circular  opening  in  the  movable  top  above  the  jacketed  stove  is 
24  inches  diameter. 

A  small  closet  is  provided  for  the  teacher. 

Plates  IV,  V  and  VI .  Basement,  floor  plan  and  plan  and  sections 
of  heating  and  ventilating  apparatus  for  a  one-story  two-room  wooden 


134 


THE   SCHOOL   HOUSE. 


n 


THE    SCHOOL    HOUSE. 


135 


136 


THE    SCHOOL    HOUSE. 
PLATE  VI. 


A—  rf 


SECTION  THROUGH  VENT  SMAFT 


THE   SCHOOL    HOUSE.  137 

schoolhouse,  intended  to  accommodate  forty-eight  pupils  in  each 
room. 

The  rooms  are  28  by  32  by  12  feet,  lighted  on  two  sides  from 
the  left  and  rear  of  the  pupils. 

The  teachers'  platforms  are  omitted  and  a  table-desk  provided  in 
each  room. 

The  pupils'  outer  garments  are  hung  on  racks  in  the  corridor,  in 
which  is  a  well-trapped  sink  and  a  looking-glass. 

The  basement  is  9  feet  9  inches  high,  well  lighted,  the  bottom 
concreted  and  covered  with  half  an  inch  of  Portland  cement,  and 
contains  separate  rooms  for  boys  and  girls,  sanitary  closets,  coal- 
bins,  cold-air  room,  furnaces  and  vent-shaft  heaters.  A  well- 
trapped  sink  is  also  provided. 

If  double  run  of  sash  or  outside  windows  are  provided  for  the 
class-rooms,  especially  if  the  building  is  in  an  exposed  location,  a 
considerable  saving  can  be  made  in  the  amount  of  coal  required. 

The  school-rooms  are  heated  by  a  large-size  furnace  encased  in 
a  double  casing  of  galvanized  iron  set  up  pside  a  cold-air  room, 
which  is  built  of  brick.  If  desired,  an  additional  covering  of  non- 
heat-conducting  material  can  be  added  to  the  outer  casing  of 
the  furnace 

The  fresh  air  is  admitted  to  the  cold-air  room  through  two 
windows  hinged  and  protected  on  the  outside  by  a  stout  wire 
grating,  and  provided  with  cords  and  pulleys  for  regulating  the 
amount  of  air  admitted. 

A  pit  extends  around  and  under  the  furnace,  causing  the  air 
to  be  more  evenly  distributed  than  by  the  usual  method  of  set- 
ting. The  space  between  the  two  casings  prevents  the  air  being 
too  rapidly  cooled  from  the  outside  while  and  after  passing  the 
fire-pot. 

Over  the  top  of  the  furnace  are  the  mixing-valves  for  regulating 
the  temperature  of  the  air  for  the  school-rooms.  The  cold  air 
for  mixing  passes  over  the  top  casing  of  the  furnace  direct  to  the 
mixing-valves,  each  of  which  is  operated  from  the  school-room 
by  pulleys,  chain  and  catch. 

The  warm-air  ducts  are  24  by  30  inches  in  cross-section.  The 
warm  air  is  admitted  into  each  class-room  through  an  opening 
30  by  30  inches,  covered  by  a  wire  grill  set  in  a  channel-iron 
frame.  The  warm-air  inlets  are  placed  on  the  inner  or  warm  side 
of  the  room,  but  near  the  outer  or  rear  wall  of  the  building,  and 

NOTE.  — The  method  of  setting  this  furnace  was  designed  by  the  writer  and  has  given 
very  satisfactory  results  where  used. 


138  THE    SCHOOL   HOUSE. 

the  bottom  of  the  grill  is  eight  feet  above  the  floor.  The  temperature 
is  regulated  by  the  mixing-valves  over  the  furnace. 

A  four-inch  diameter  metallic  thermometer  with  perforated  back 
and  sides,  placed  on  the  wire  grill  about  two-thirds  up  from  the 
bottom,  half-way  between  the  sides,  will  be  of  much  service  to  the 
teacher  in  regulating  the  temperature. 

Two  or  three  pieces  of  ribbon  about  one-quarter  inch  wide  and 
about  one  foot  long,  tied  into  the  grill  just  below  the  thermometer, 
will  enable  the  teacher  to  judge  of  the  amount  and  velocity  of  the 
incoming  air. 

A  thermometer,  placed  at  about  the  level  of  the  pupils'  heads, 
when  seated,  and  located  on  the  partition  in  rear  of  the  teacher's 
desk,  should  be  provided ;  also  one  for  outside  use,  placed  where 
the  sun  will  not  shine  directly  on  it,  for  the  janitor's  use. 

The  small  supplementary  heater  for  the  corridor  or  hallway  is 
intended  for  use  in  very  cold  or  wet  weather,  also  for  drying  the 
pupils'  clothing  and  for  a  foot-warmer  and  drier.  It  also  provides 
for  moderately  warming  the  basement.  Each  warm-air  pipe  from 
this  heater  is  provided  with  a  damper.  This  heater  receives  its 
air  supply  through  a  galvanized-iron  duct  and  hinged  window 
covered  on  the  outside  with  stout  wire-netting,  and  draws  the  air 
from  under  the  front  platform.  In  the  stair  risers  in  front  and  on 
each  end  of  the  outside  front  platform  are  wire-covered  openings 
to  admit  fresh  air  to  supply  the  heater. 

A  register  face,  27  by  38  inches,  with  a  hinged  door  underneath,  is 
provided  in  the  floor  of  the  closet  between  the  two  class-rooms,  and 
opens  into  the  cold-air  room  below  for  the  purpose  of  rotating  the  air 
through  the  building  at  night  or  when  the  schools  are  not  in  session. 

The  foul  air  from  each  school-room  is  taken  from  the  floor  level 
at  the  inner  or  warm  corner  of  the  room  through  a  register  face 
(without  valves)  27  by  38  inches  and  a  galvanized-iron  duct  down 
to  the  bottom  of  the  foul-air  shaft  or  stack,  which  it  enters  through 
an  opening  24  inches  high  by  30  inches  long.  A  valve  or  damper 
operated  by  a  chain  from  the  school-room  is  provided  in  each 
galvanized-iron  foul-air  duct. 

The  brick  foul-air  shaft  is  36  by  48  inches  inside,  and  has  a  brick 
partition  extending  across  the  narrowest  way  to  act  as  a  cut-off  and 
to  prevent  cross  drafts  from  the  ducts.  This  partition  extends 
above  the  top  of  the  foul-air  entrances  and  on  top  of  it  is  placed  a 
cast-iron  stove  or  u  stack  heater"  with  its  smoke-pipe  connected 
with  a  separate  smoke  flue.  The  fuel  door  and  draft  for  the  stack 
heater  are  tended  from  outside  the  shaft. 


THE    SCHOOL    HOUSE.  139 

A  damper  is  provided  in  the  smoke-pipe  and  operated  by  a  rod 
extending  through  to  the  front  of  the  shaft.  A  manhole  door  is 
provided  under  the  stack  heater  and  in  the  front  of  the  shaft. 

The  foul  air  from  the  corridor  or  hallway  is  taken  out  through 
a  wire  grill,  12  by  12  inches,  under  the  sink  and  directly  into  the 
vent  shaft;  a  galvanized-iron  deflector,  hinged  at  the  bottom  and 
arranged  to  open  or  close  by  a  chain  and  catch  is  placed  at  this 
opening.  This  vent  opening  is  desirable  for  removing  the  foul  air 
and  odors  from  the  clothing  and  preventing  them  from  entering 
the  school-room.  ^ 

The  sanitary  closets  in  the  basement  are  of  the  individual,  short 
hopper,  automatic  flushing  pattern,  having  a  four-inch  diameter 
seat  vent  connecting  with  a  duct  (increasing  in  size  as  each  closet 
is  added)  to  the  sanitary  vent-flue,  which  is  16  by  48  inches,  inside 
dimensions. 

The  boys'  urinal  is  of  oiled  slate,  with  perforated  flushing  pipe 
at  the  top  and  vented  into  the  same  vent-flue  as  the  closets. 

An  underground  drain-pipe  is  provided  for  the  closets  and  urinal, 
and  connects  with  a  sewer  or  a  double  leaching  cesspool  well  in 
the  rear  of  the  building. 

No  separate  vent  opening  is  provided  for  the  basement,  as  it  will 
be  well  ventilated  through  the  sanitary  fixtures  and  vent-shaft  if 
the  stack-heater  which  is  placed  in  the  sanitary  vent-shaft  is 
properly  located  and  a  fire  maintained  therein. 

Hose  for  washing  out  should  be  provided  and  the  underground 
drain  thoroughly  trapped. 

If  there  is  no  available  water  supply  for  the  sanitary  fixtures  they 
should  be  placed  outside  in  a  separate  building  and  at  a  good 
distance  from  the  school. 

A  matched  board  removable  porch  on  the  front  platform  is  an 
advantage  in  winter  and  will  save  fuel. 

Plates  VII,  VIII  and  IX  show  plans  of  basement,  first  and  second 
stories,  and  a  section  through  vent-shaft  for  a  two-story  two-room 
schoolhouse. 

This  building  belongs  to  a  class  of  which  many  were  built  in 
Massachusetts  some  years  ago  and  were  practically  without  ventila- 
tion, except  by  means  of  windows  and  doors.  They  were  often 
heated  by  wood-burning  stoves. 

The  heating  and  ventilation  of  such  schoolhouses  may  be  made 
satisfactory  if  constructed  as  shown  herein. 

In  the  basement  is  located  a  large  brick-set  furnace  with  a  brick 
cold-air  room,  connected  with  the  outside  air  by  a  galvanized-iron 


140 


THE    SCHOOL   HOUSE. 


THE    SCHOOL   HOUSE. 


141 


142 


THE    SCHOOL   HOUSE. 


THE    SCHOOL    HOUSE.  143 

duct  six  feet  wide  by  two  feet  deep.  The  duct  enters  at  the  top  of 
the  cold-air  room  and  is  provided  with  a  damper  and  the  outer 
opening  is  protected  by  a  stout  wire  grill. 

Two  galvanized-iron  ducts,  24  by  36  inches,  supply  warm  fresh 
air,    one    to    each    class-room.      These    ducts   are    provided    wfth- 
mixing- valves  or  dampers  to  regulate  the  temperature  of  the  air  for 
the  school -rooms. 

The  setting  of  the  furnace  and  arrangement  of  the  warm»-air 
ducts  are  as  shown  in  plates  VII,  VIII  and  IX.  In  the  floor  of 
the  first  story  is  a  cast-iron  register  without  valves,  but  provided 
with  a  hinged  door  opening  down  into  the  cold-air  room  for  rotating 
air  within  the  building  when  the  schools  are  not  in  session. 

The  ventilation  of  the  building  is  by  a  brick  stack,  inside  of 
which  are  the  smoke  flues.  The  foul  air  from  the  lower  school- 
room is  taken  down  through  a  cast-iron  register  face,  27  by  38 
inches,  in  the  floor  and  a  galvanized-iron  duct,  which  is  gradually 
reduced  in  size  to  where  it  enters  the  bottom  of  the  vent  shaft,  at 
which  point  it  is  24  by  30  inches  area.  The  register  in  the  floor 
has  no  valves,  but  a  damper  operated  by  a  chain  and  catch  is 
provided.  t 

In  the  vent  shaft,  placed  on  iron  bars  just  above  the  foul-air 
entrance,  is  a  stove  or  "stack-heater"  to  raise  the  temperature  of 
the  outgoing  air  and  produce  a  good  outflow  up  through  the  vent 
shaft. 

The  stack-heater  should  always  receive  its  air  for  draft  for  the 
fire  from  outside  the  shaft.  If  the  air  for  the  combustion  of  the 
fuel  in  the  stack-heater  is  taken  from  inside  the  stack,  difficulty 
will  be  experienced  in  keeping  the  fire  burning  properly.  The 
air  rushing  up  011  the  outside  of  the  heater  will  in  a  great  measure 
destroy  the  draft  for  the  fire. 

The  foul  air  from  the  second  story  is  taken  directly  into  the  vent 
shaft  through  an  opening  30  inches  long  by  24  inches  high,  the 
bottom  of  which  is  at  the  floor  level. 

A  galvanized-iron  curved  damper  is  provided  at  this  opening, 
and  the  opening  is  covered  by  a  stout  wire  grill. 

The  air  brought  down  from  the  lower  room  and  heated  by  the 
stack-heater  passes  up  on  the  back  of  the  curved  damper  and  causes 
a  good  outflow  of  air  from  the  second-story  room.  In  each  cloth- 
ing room  is  a  10  by  12-inch  opening  with  a  valved  register  and 
connecting  with  the  vent  shaft. 

Should  it  be  desired  to  provide  foot-warmers  and  heat  the 
clothing  rooms,  it  is  advisable  to  use  a  small  furnace  (set  up  about 


144 


THE   SCHOOL   HOUSE. 


where  the  small  coal-bin  is  located),  which  has  pipes  to  the  floor 
of  each  clothing-room.  The  supply  of  air  for  the  small  furnace 
should  be  taken  from  outside  the  building,  preferably  from  under 
the  front  platform,  which  should  have  openings  to  freely  admit  air. 
A  rotating  register  can  also  be  used  with  the  small  furnace. 

When  an  attempt  is  made  to  heat  the  school-rooms  and 
the  clothing-rooms  from  the  same  furnace  it  is  hardly  ever  suc- 
cessful. 

When  the  fresh-air  supply  for  the  large  furnace  is  shut  or  partly 
shut  off  there  will  be  a  reversal  of  the  air  currents  in  the  pipes  to 
the  lower  clothing-rooms,  and  air  will  be  taken  down  over  the  top 
of  the  furnace  and  be  carried  up  into  the  school-rooms. 

Two  standard  size  school-rooms  are  all  that  should  be  heated  by 
a  furnace,  even  if  it  is  a  large  one. 

PLATE   X. 


5HOWIMO     HLATINGS  VCNTILATION 


BASCAENT 
FOOD.    £OQA   SCHOOL 


Plates  X,  XI,  XII,  XIII  and  XIV.— Plans  and  sections  of  the 
heating  and  ventilating  apparatus  for  a  two-story,  four-room  school- 
house,  to  be  built  of  red  brick  with  granite  trimmings,  slate  roof, 
and  copper  gutters.  / 

In  the  basement,  which  is  10  feet  6  inches  high  and  well  lighted, 
are  located  the  heating  apparatus,  fuel-room,  cold-air  room, 
sanitary  fixtures  and  rooms  for  boys  and  girls,  also  bicycle  racks. 


THE   SCHOOL   HOUSE, 


145 


PLATE   XI. 


.  H\ 


Fouc  Cocn  SCMODL 

SHOWING  HtATiNC'-- VEMTILATION 


PLATE   XII. 


CLAVj    DOQA 


c  uvss  r.'non. 


MCOND    STORY 
COQA     5CHOOL 


SHOWING  MATING NVCHTU.ATKJM 


146 


THE    SCHOOL    HOUSE. 


THE    SCHOOL   HOUSE.  147 

Bicycle  runs  are  provided  at  each  outside  basement  entrance.  A 
well-trapped  sink  is  placed  in  each  basement iroom. 

The  basement  floor  is  of  concrete  and  covered  with  Portland 
cement. 

On  the  first  floor  are  two  class-rooms  28  by  32  by  12  feet, 
intended  to  accommodate  49  pupils  each,  well  lighted  and  the  seats 
to  be  so  arranged  that  the  light  will  come  from  the  left  and  rear  of 
the  pupils.  There  is  also  a  small  room  for  use  of  the  teachers. 
Suitable  closets  are  provided  in  each  class-room  and  in  the 
teachers'  room. 

In  the  second  story  are  two  class-rooms  similar  to  those,  in  the 
first  story,  also  a  small  room  that  can  be  used  as  a  library  or  store- 
room, or  as  a  superintendent's  room. 

The  corridors  are  1 5  feet  wide  and  well  lighted  ;  clothing  is  hung 
on  racks  on  the  school-room  side. 

The  heating  for  the  class-rooms  is  done  by  two  large-size  brick- 
set  furnaces.  The  corridors  and  two  small  rooms  are  heated  by 
a  small  sectional  cast-iron  boiler,  which  is  also  intended  to  furnish 
heat  for  the  ventilating  flues.  Foot-warmers  heated  by  the  boiler 
are  placed  in  the  floor  of  the  lower  corridor,  for  use  in  cold  or  wet 
weather. 

A  disc  fan,  operated  by  an  electric  motor,  is  provided  for 
furnishing  an  abundant  supply  of  fresh  air  in  mild  or  moderately 
warm  weather.  In  cold  or  windy  weather  the  furnaces  are  to  be 
used  by  the  gravity  system. 

If  electricity  is  not  available  for  running  the  fan  it  can  be 
omitted,  also  the  partition  wall  in  which  the  fan  is  located.  In 
such  case  the  furnaces  can  be  placed  three  feet  nearer  the  rear 
wall. 

In  cold  weather,  when  it  is  desirable  to  quickly  warm  the  class- 
rooms before  the  school  session  begins,  the  outside  windows  in  the 
cold-air  room  and  the  dampers  in  the  school-room  and  in  the 
corridor  vents  being  closed,  the  rotating  register  in  the  floor  of  the 
closet  between  the  two  lower  class-rooms  and  all  the  doors  in  the 
class-rooms  opened,  the  motor  is  started  and  the  air  is  rotated 
through  the  building. 

If  no  fan  is  installed,  the  same  arrangement  of  cold-air  windows, 
dampers,  rotating  register  and  doors  should  be  made  and  the  air 
rotated  by  gravity. 

Before  the  school  session  commences  or  the  pupils  are  admitted 
to  the  building,  the  vent-dampers  should  be  opened,  the  rotating 
register  and  doors  closed  and  the  cold-air  windows  opened.  Under 


148  THE    SCHOOL   HOUSE. 

no  conditions  should  the  rotation  of  air  through  the  building  be 
allowed  while  the  schools  are  in  session. 

When  using  the  fan  during  school  hours,  two  windows  and  the 
doors  in  the  partition  in  the  cold-air  room  should  be  closed,  the  air 
taken  in  through  the  middle  window  opposite  the  fan  and  driven 
through  the  fan-opening.  When  using  the  gravity  system  all  three 
windows  and  the  two  doors  in  the  partition  should  be  opened. 

The  fresh  warm-air  flues  for  the  class-rooms  are  of  brick, 
24  by  36  inches  (area  six  square  feet),  and  have  mixing-valves  or 
dampers,  operated  by  chain,  catch  and  pulley,  by  means  of  which 
the  temperature  of  the  incoming  air  can  be  properly  regulated  by 
the  teachers  without  materially  decreasing  the  volume. 

The  vent-flues  for  the  class-rooms  are  x>f  brick,  24  by  30  inches 
(area  five  square  feet) .  The  vent-flues,  with  the  exception  of  the 
sanitary  vents,  have  curved  galvanized-iron  dampers,  operated  by 
chain  and  catch.  The  sanitary  vents  should  not  be  closed  at 
any  time. 

In  each  vent-flue,  except  the  corridor  vent,  there  are  placed  four 
sections,  of  five  square  feet  each,  of  cast-iron  radiators.  These 
are  placed  just  above  the  top  of  the  inlet  vent,  spaced  and  inclined 
up  and  across  the  flue.  In  the  corridor  vent  there  are  but  two 
sections,  or  ten  square  feet  of  radiation. 

These  radiators  are  connected  with  the  small  boiler  and  separately 
valved  on  each  supply  and  return  pipe. 

At  night,  or  when  the  building  is  not  occupied,  the  steam  is 
shut  off  from  the  vent-flue  radiators  and  the  vent  dampers  closed. 

In  extremely  cold  or  windy  weather  it  will  not  be  necessary  to 
keep  steam  on  the  vent-flue  heaters,  and  in  some  cases  of  this  kind 
the  dampers  can  be  partly  closed,  but  in  mild,  calm  or  warm 
weather  steam  should  be  kept  on  these  heaters. 

The  use  of  unsightly,  costly  and  often  worse  than  useless 
deflectors,  diffusers  and  flap-valves  is  rendered  unnecessary  by 
properly  locating  the  supply  and  vent-flues  and  having  them  of 
ample  size  and  properly  valved. 

The  success  of  any  system  of  heating  and  ventilation  depends 
considerably  on  the  good  judgment  of  the  janitor  in  operating  the 
apparatus,  and  he  should  be  carefully  instructed  in  his  duties. 

The  teachers  should  also  be  instructed  in  the  manner  of  operating 
the  mixing-valves  or  dampers  in  the  warm-air  flues  and  the  dampers 
in  the  vent-flues. 

Plates  XV,  XVI  and  XVII. — Plans  for  a  two-story  five-room 
school  building  and  for  the  heating  and  ventilation  of  the  same. 


THE    SCHOOL   HOUSE. 


149 


The  building  is  to  be  constructed  of  red  brick  with  granite 
trimmings,  slated  roof  and  copper  gutters. 

There  are  four  class-rooms  and  one  large  assembly-room  or  hall, 
which  can,  if  desired,  be  divided  into  two  class-rooms ;  also  two 


PLATE   XV. 


5CALF  OF  FEET 


•FIVE  ROCA  SCHOOL 

BASEMENT" 
•SHOWING-HEATING- AND-VENT1LATION- 


small  rooms  in  the  second  story  for  the  use  of  the  teachers.  In 
the  basement,  which  has  a  concrete  floor  with  a  covering  of 
Portland  cement,  are  two  sanitary  rooms,  cold-air  rooms,  boiler 
rooms  and  fuel  rooms. 

The  class-rooms  are  of  standard  size,  28  by  32  by  12  feet, 
intended  to  accommodate  49  pupils  each.  Transoms  are  over  each 
door,  except  in  the  basement.  The  doors  from  the  class  and 
assembly-rooms  open  into  the  corridors,  and  each  has  a  large 


150 


THE    SCHOOL   HOUSE. 


glass  panel   in  the  center  to   enable  the   teachers   to   see  into  the 
corridors. 

The  corridors  are  15  feet  wide,  with  special  racks  on  the  walls 
for  clothing. 

PLATE  XVI. 


•FIVEROOA\5CHGDL- 

FlRSTSTODY- 
SnOWING-HEATIN&'AND-VENTrLATION 


The  warm  fresh  air  is  admitted  into  the  class-rooms  through 
openings 'covered  by  wire  grills  36  by  30  inches.  The  bottom  of 
these  openings  is  eight  feet  above  the  floor.  In  the  assembly  room 
the  grills  are  54  by  30  inches.  The  warm-air  flues  to  the  class- 
rooms are  36  by  24  inches  (six  square  feet),  and  in  the  assembly 
room  are*54  by  24  inches  each.  Each  warm-air  flue  is  provided 
with  a  galvanized-iron  damper  or  mixing-valve  to  regulate  the 


^ 


THE   SCHOOL   HOUSE, 


151 


temperature  of  the  incoming  air  without  materially  decreasing  the 
supply. 

The  foul  air  is  taken  out  at  the  floor  level  through  wire  grills, 
30  by  24  inches  (five  square  feet) .  In  the  assembly  room  the 
outlet  grill  is  72  by  24  inches  (12  square  feet). 


PLATE   XVII. 


HALL.' 


•FIVE  ROQA15CHODL- 

•  SECOND  STORY- 
.-5HOWING-HEAT1NG-AND-VENTILAT1ON- 


Each  foul-air  outlet  vent,  except  the  sanitary  vents,  is  provided 
with  a  galvanized-iron  damper  to  regulate  the  outflow  or  shut  it 
off  when  the  building  is  not  occupied. 

In  each  class-room  vent-flue  are  placed  four  sections  of  cast- 
iron  smooth-surface  radiators,  each  having  five  square  feet  of 
radiating  surface  (a  total  of  20  square  feet).  In  the  assembly- 


152  THE    SCHOOL    HOUSE. 

room  vent-flue  are  placed  nine  sections  (45  square  feet)  of  the 
same  kind  of  radiators.  These  radiators  are  placed  about  one  foot 
above  the  top  of  the  vent  opening  from  the  room,  evenly  spaced, 
and  inclined  upward  and  across  the  flue. 

A  vent -flue,  24  by  24  inches  inside  measurement,  is  provided  for 
the  corridors,  both  corridors  venting  into  the  same  flue,  and  15 
square  feet  of  radiation  is  placed  above  the  lower  corridor  vent 
opening. 

The  sanitary  vent-flues  are  each  20  by  24  inches  and  contain  15 
square  feet  of  radiation. 

The  heating  is  by  a  horizontal  tubular  boiler,  54  inches  in 
diameter,  15  feet  3  inches  long,  containing  60  three-inch  tubes,  14 
feet  long,  and  rated  at  48  horse-power. 

A  small  sectional  boiler  is  also  provided  for  heating  the  vent- 
flues  when  the  large  boiler  is  not  in  use. 

The  piping  for  the  vent-flues  is  so  connected  that  either  the 
large  or  small  boiler  can  be  used  as  desired.  Each  vent-flue  heater 
is  separately  valved,  both  on  the  supply  and  return  pipes. 

The  radiation  for  each  class-room  consists  of  400  square  feet-of 
cast-iron  indirect  pin  radiators,  of  20  square  feet  per  section,  made 
into  three  stacks  of  120,  140  and  140  square  feet  —  one  section, 
two  sections  or  three  sections  to  be  used  as  may  be  required.  Each 
section  is  to  be  separately  piped  and  valved. 

The  assembly-hall  has  two  distinct  groups  of  indirect  radiation, 
480  square  feet  each,  and  each  group  is  made  up  of  four  stacks, 
separately  piped  and  valved.  Around  the  outside  walls  are  two 
lines  of  one-and-one-fourth-inch  steam-pipe  for  use  when  the 
assembly-hall  is  not  occupied. 

Two  foot-warmers,  each  of  120  square  feet,  of  the  same  kind  of 
radiation  used  for  the  class-rooms,  are  provided  in  the  lower 
corridor. 

Two  lines  of  one-and-one-fourth-inch  steam-pipe  are  also  pro- 
vided in  the  corridors  and  placed  under  the  clothing  racks  for 
drying  the  clothing  in  stormy  weather. 

The  sanitary  rooms  are  heated  by  four  lines  of  one-and-one- 
fourth-inch  pipe,  placed  near  the  ceiling. 

Direct  radiators  are  placed  in  the  teachers'  rooms  and  toilets. 

In  the  floor  of  a  closet  in  each  class-room  is  placed  a  register 
connecting  with  the  cold-air  room  below.  A  tight-fitting  shutter 
of  galvanized  iron  is  placed  below  the  register  to  shut  off  the  cold 
air  from  below  when  the  register  is  not  open.  These  registers, 
called  rotating  registers,  are  for  rotating  the  air  through  the  build- 


THE    SCHOOL    HOUSE. 


153 


ing  when  the  schools  are  not  in  session.  This  is  clone  as  pre- 
viously stated  in  the  description  of  a  two-story  four-room  school 
building. 

The  ventilation  of  the  sanitary  rooms  and  basement  is  through 
the    fixtures,   each    closet   having  a   four-inch   diameter   seat   vent 

PLATE   XVIII. 


5 ix  ROOA  SCHOOL- 

•BASEMENT' 
•5H  OWING  ttEATlNG&VENTllATlON' 

connected  with  a  galvanized-iron  duct  leading  from  each  line  of 
closets  and  from  the  urinal  to  a  steam-heated  vent -flue. 

The  air  from  the  sanitary  rooms  being  taken  out  through  the 
closets  and  urinal  vents  prevents  odors  passing  out  from  these 
rooms  up  into  the  building,  as  is  sometimes  the  case  when  the 
room  is  vented  by  an  outlet  separate  from  that  provided  for  the 
sanitary  fixtures,  or  where  air  is  forced  into  the  sanitary  room  by  a 
fan  or  gravity  supply  from  the  heating  system. 


154 


THE    SCHOOL   HOUSE. 


A  plenum  condition  should  never  be  allowed  in  such  rooms. 
An  exhaust  should  be  used  instead  of  a  plenum. 

Sufficient  air  will  be  supplied  to  keep  the  sanitary  rooms  free  from 
odors,  if  taken  into  the  sanitary  rooms  through  a  wire  grill  placed 
in  the  bottom  of  the  doors  leading  from  the  basement  corridor,  and 
if  the  sanitary -vent  flues  are  properly  heated. 

PLATE   XIX. 


SCHOOL- 
SCALCormt  F  \RST  STORY 

•SHOWING  WF.ATING& VENTILATION- 

Plates  XVIII,  XIX  and  XX. — Plans  for  a  six-room  school 
building  and  for  its  heating  and  ventilation. 

The  building  is  to  be  constructed  of  red  brick  with  terra-cotta 
trimmings,  slated  roof  and  copper  gutters. 

There  are  six  class-rooms,  each  28  by  32  by  12  feet  and  intended 
to  accommodate  49  pupils.  In  the  second  story  are  two  small 
rooms'for  the  teachers'  use. 


THE    SCHOOL    HOUSE. 


155 


The  seats  in  four  class-rooms  are  to  be  arranged  to  receive  the 
light  from  the  left  and  rear,  and  in  two  class-rooms  the  light  is 
chiefly  from  the  left. 

The  corridors  are  15  feet  wide  and  contain  the  clothing  racks. 
Doors  from  the  corridors  to  the  class-rooms  have  each  a  latge- 
center  panel  of  heavy  glass,  and  transoms  are  provided  over  the  doors. 

In  the  basement  are  three  rooms,  a  divided  corridor,  fuel  and 
cold-air  rooms.  ^ 

PLATE   XX. 


5 IX  ROO/v  .!>CHbOL- 

•SECOND  MOPY- 
•SHOWING  HF.ATING  &  VLNTILATION 


The  fresh  warm-air  flues  and  the  vent -flues  for  the  class-rooms 
are  of  the  same  size  and  fitted  with  mixing-valves,  dampers  and 
steam  radiation,  as  previously  described  for  a  four  or  five-room 
school -house,  except  that  the  sanitary  vent-flues  are  24  by  24 
inches  area. 

Rotating  registers  are  also  provided. 

There  are  two  foot-warmers  in  the  lower  corridor. 


156  THE    SCHOOL    HOUSE. 

The  general  plan  of  the  building  is  the  same  as  that  given  for  a 
five-room  school,  except  that  the  assembly  hall  in  the  five-room 
building  is  replaced  by  two  class-rooms,  and  the  heating  is  by  a 
combination  of  furnaces  and  steam  heat.  The  six  class-rooms  are 
heated  by  three  large  brick-set  furnaces,  two  rooms  for  each 
furnace.  A  cast-iron  sectional  boiler  is  provided  for  heating  the 
corridors,  vent-flues,  foot-warmers  and  teachers'  rooms. 

If  desired,  the  boiler  may  be  of  sufficient  size  to  warm  the 
basement  rooms  by  lines  of  one-and-one-fourth-inch  steam-pipes 
placed  near  the  ceiling. 

By  the  use  of  this  boiler  very  satisfactory  results  are  obtained, 
and  the  number  of  fires  reduced  from  what  would  be  required  if 
coal-burning  stack-heaters  and  an  additional  furnace  were  used  to 
heat  the  corridor  and  vent -flues. 

Plates  XXI,  XXII,  XXIII,  and  XXIV.  — Plans  for  a  grammar 
school  building. 

The  building  is  to  be  constructed  of  light  mottled  brick  with 
granite  trimmings  and  slated  roof,  containing  six  class-rooms,  one 
recitation-room,  a  manual-training  room,  two  teachers'  rooms,  two 
sanitary  rooms,  boiler-room,  coal-room  and  three  cold-air  rooms, 
besides  the  corridors  and  stairways.  There  are  four  class-rooms 
each  28  by  32  by  12  feet,  two  class-rooms  29  by  32  by  12  feet, 
each  accommodating  forty-nine  pupils.  The  basement  is  twelve 
feet  high,  except  the  boiler-room  and  coal -room,  which  are  two  feet 
deeper,  or  fourteen  feet  in  the  clear.  The  basement  entrances  are 
built  with  a  bicycle  run  to  take  bicycles  down  to  the  places  provided 
for  them. 

The  corridors  are  fifteen  feet  wide,  with  walls  of  smooth  water- 
struck  brick  without  wood  finish,  being  painted  with  light-colored 
gloss  paint.  Clothing  is  to  be  hung  on  special  racks  fastened  to 
the  walls,  and  there  are  two  lines  of  IJ-inch  steam-pipes  below  the 
racks  and  near  the  floor  for  drying  and  warming  clothing  in  bad 
weather.  Two  foot-warmers  are  provided  in  the  lower  corridor. 
The  heating  is  done  by  a  two -pipe  gravity  return  steam  system. 

The  two  teachers'  rooms  are  heated  by  direct  radiators,  the 
manual -training  room  in  the  basement  by  four  lines  of  1^-inch 
steam-pipe  near  the  ceiling  and  also  by  indirect  radiators. 

The  boys'  and  girls'  sanitary  rooms  are  to  be  heated  by  four  lines 
of  1^-inch  steam-pipe  near  the  ceiling,  and  ventilated  through  the 
sanitary  fixtures,  the  seats  having  4 -inch  diameter  vents  connecting 
with  steam-heated  vent-flues,  with  which  the  boys'  urinal  is  also 
connected.  Air  is  drawn  into  these  rooms  through  wire  grills  in 


THE    SCHOOL    HOUSE. 


157 


158 


THE    SCHOOL    HOUSE. 


THE    SCHOOL    HOUSE. 


159 


160 


THE    SCHOOL    HOUSE. 


THE    SCHOOL    HOUSE.  161 

the  bottom  of  the  corridor  doors,  and  the  natural  leakage  around 
the  windows  and  the  removal  of  the  foul  air  through  the  seat  and 
urinal  vents  will  properly  ventilate  these  rooms  and  prevent  odors 
from  passing  up  and  into  the  building. 

In  the  floor  of  the  first  story  are  three  rotating  registers  JEon 
rotating  the  air  through  the  indirect  radiators  when  the  schools  are 
not  in  session.  The  air  for  the  foot-warmers  is  rotated  from  the 
corridor  at  all  times.  A  vent  is  provided  in  each  corridor,  both 
corridors  being  vented  into  the  same  shaft.  Direct  radiation  is 
provided  in  each  vestibule. 

The  warm-air  flues  to  the  class-rooms  are  24  by  36  inches  in 
cross-section,  and  enter  the  rooms  eight  feet  above  the  floor  through 
openings  covered  by  a  wire  grill  36  by  30  inches.  Each  warm-air 
flue  is  fitted  with  a  mixing-valve  or  damper  for  regulating  the  tem- 
perature of  the  incoming  air. 

An  adjusting  damper  is  also  provided  for  each  warm-air  flue  for 
regulating  the  amount  of  air  for  each  room,  as  this  will  vary  accord- 
ing to  the  height  of  the  flue  or  its  location  with  regard  to  the 
prevailing  winds. 

Each  vent-flue,  except  the  sanitary,  is  to  be  provided  with  a 
galvanized-iron  damper  for  regulating  the  outflow  of  air. 

In  each  class-room  vent-flue  there  is  twenty  square  feet  of  radiat- 
ing surface  of  IJ-inch  steam-pipe  made  into  the  form  and  placed 
as  indicated  in  the  section  showing  the  vent-flues. 

The  vent  from  the  recitation  room  is  carried  down  and  through 
a  galvanized-iron  duct  (No.  24  gauge  iron)  on  the  basement  ceiling 
to  the  brick  vent-flue  for  this  room,  which  should  have  twenty-five 
square  feet  of  steam-pipe  radiation,  placed  about  on  a  level  with  the 
floor  of  the  first  story. 

Each  sanitary  vent  has  twenty  square  feet  of  the  same  kind  of 
radiation. 

The  building  is  to  be  heated  by  two  horizontal  tubular  boilers  of 
27  horse-power  each,  and  a  cast-iron  sectional  boiler  for  heating 
the  vent-flues  when  the  larger  boilers  are  not  in  use  in  moderately 
warm  weather.  These  sectional  boilers  are  generally  designated 
"  summer  boilers."  The  boilers  are  to  be  so  piped  and  valved  that 
either  or  all  of  them  can  be  used  as  desired. 

The  recitation-room  is  to  have  300,  the  two  middle  class- 
rooms 380,  and  the  four  corner  class-rooms  400  square  feet  of 
cast-iron  indirect  radiation  of  twenty  square  feet  per  section,  made 
into  three  sections  for  each  stack,  separately  piped  and  valved, 
in  order  that  the  amount  in  use  can  be  regulated  according  to  the 


162 


THE    SCHOOL    HOUSE. 


weather.  The  vent-flue  heaters  are  to  be  separately  valved  and 
piped. 

Hand  bowls  and  faucets  are  provided  in  the  first  and  second  story 
corridors  and  cast-iron  sinks  in  the  boys'  and  girls'  sanitary  rooms, 
bowls  and  sanitary  fixtures  in  the  teachers'  rooms  in  the  second 
story.  Mirrors  are  placed  over  the  bowls  and  sinks  for  the  pupils' 
use  and  in  the  teachers'  toilets. 

Hose  is  to  be  provided  for  use  in  the  basement.  It  is  advisable 
to  install  a  stand-pipe  and  hose  in  the  basement  and  each  corridor 
for  use  in  case  of  fire. 

Sections  are  given  showing  the  arrangement  of  the  indirect  radia- 
tors, mixing-valves  and  warm-air  flues,  the  foul-air  flues,  heaters 
and  dampers,  adjusting  dampers,  rotating  register  and  windows  in 
the  cold-air  rooms,  clothing  racks  and  the  catches  for  holding  the 
chains  for  the  mixing-damper  and  vent  dampers. 

PLATE   XXV. 


-BASEMENT-        • 

-UGHT  RDM  SCHOOL 


THE    SCHOOL    HOUSE. 


163 


Plates  XXV,  XXVI,  XXVII  and  XXVIII. —  Plans  for  a  two- 
story,  eight -room,  brick  school  building,  showing  the  heating, 
ventilating  and  sanitary  appliances. 

A  combination  of  the  gravity  and  mechanical  systems  of  heating 
and  ventilation  is  used. 

In  the  gravity  system  there  are  400  square  feet  of  indirect  cast- 
iron  heating  surface  for  each  school -room.  This  is  divided  into 
stacks  of  100,  140  and  160  square  feet  for  each  class-room,  separ- 
ately piped  and  valved,  in  order  that  either  a  part  or  the  whole  can 
be  used  as  desired,  and  is  sufficient  to  meet  the  requirements  of 
heating  and  ventilation  in  the  coldest  weather  that  occurs  in 
Massachusetts. 

Fresh  air  is  admitted  through  the  windows  in  the  two  cold-air 
rooms  in  the  basement,  when  the  gravity  system  is  in  use  (the  ducts 

PLATE    XXVI. 


164 


THE   SCHOOL   HOUSE. 


leading  from  the  fan  being  then  closed)  in  cold  weather,  when  the 
difference  between  the  inside  and  outside  temperature  is  sufficient 
to  furnish  a  full  supply  of  warm,  pure  air  by  gravity  flow. 

In  the  floor  of  the  closet  between  the  rooms  on  each  side  of  the 
lower  corridor  there  is  a  rotating  register  connecting  with  the  cold- 
air  rooms  below. 

PLATE   XXVII 


-  CORRIDOR  - 


-tiECOND  5TORY- 
-ElCHT  R(X)M  SCHOOL; 


I  NC  HEATING  •-.  VENTILATION - 


In  the  basement  of  one  of  the  corridor  extensions  there  is  also  a 
supplementary  means  of  supplying  air  by  a  fan  driven  by  an  electric 
motor,  and  800  square  feet  of  indirect  cast-iron  radiation,  divided 
into  sections  of  100,  140  and  160  square  feet,  as  in  the  other  cold- 
air  rooms. 

This  part  of  the  apparatus  is  intended  to  be  used  in  moderate 
and  calm  weather,  when  the  requisite  supply  of  fresh  air  is  not 
easily  obtained  by  the  gravity  system  without  overheating,  espe- 
cially in  the  spring  and  fall  months. 


THE   SCHOOL  HOUSE. 


165 


When  in  use  the  windows  leading  from  outside  directly  into  the 
gravity  cold-air  rooms  are  to  be  closed,  and  the  sliding  damper  at 
the  entrance  of  the  galvanized-iron  ducts  into  the  gravity  cold-air 
rooms  opened,  the  windows  in  the  cold-air  corridor  extension  base- 
ment opened  and  the  fan  run  by  the  motor,  the  air  either  passing 
through  the  heated  radiators,  or,  by  means  of  a  specially  designed 
damper,  going  to  the  fan  without  passing  the  radiators.  This 

PLATE   XXVIII. 


BB-  -v  -DCTAJLb-FOR-HDXTlNCWENTlLATlXG-  ••&CTK»HHRP«»C<- 

•  EIGHT  Rf  DM-  SCHOOL- 

damper  can  be  used  as  a  mixing  damper  to  regulate  the  heat  and  allow 
more  or  less  warm  or  cold  air  to  pass  the  fan  as  may  be  desired. 

A  four-inch  diameter  metallic  thermometer,  placed  in  the  side 
of  the  galvanized-iron  duct  leading  to  the  air  rooms  at  the  bottom 
of  the  warm-air  flues,  which  go  to  the  schoolrooms,  will  enable 
the  janitor  to  regulate  the  temperature  of  the  air  sent  from  the  fan. 
Should  it  be  desired  to  use  the  fan  when  the  air  is  colder  than  the 
fan  radiation  can  properly  warm,  a  portion  of  the  radiation  in  the 
other  cold-air  rooms  can  be  used  to  good  advantage. 

By  the  use  of  this  combination  system  forty  cubic  feet  of  air  per 
minute  can  be  supplied  for  each  pupil  under  all  conditions  of 
temperature. 


166  THE    SCHOOL    HOUSE. 

While  it  may  add  somewhat  to  the  first  cost  of  the  building, 
the  effective  work  will  more  than  make  up  for  the  extra  first 
cost. 

If  electric  power  is  not  available,  the  fan  may  be  run  by  an 
engine  having  a  large  diameter,  low-pressure  cylinder.  This,  how- 
ever, will  require  a  change  in  the  piping  and  setting  up  of  this  part 
of  the  apparatus,  and  a  small  boiler  of  sufficient  size  to  run  the 

PLATE   XXIX. 


BROCK  AVE.,  5CHO0C 

NEW  BEDFORD    MASS.,U.SA. 


engine  and  also  furnish  (at  a  reduced  pressure)  steam  for  the  vent- 
flue  heaters  when  the  larger  boilers  are  not  in  use. 

In  addition  to  the  two  horizontal  tubular,  a  cast-iron  sectional 
boiler  is  supplied  for  heating  the  vent-flues  when  the  electric  motor 
is  used  or  when  the  larger  boilers  are  not  fired  up. 

The  warm-air  flues  and  the  vent-flues  are  of  the  same  size  and 
location,  and  similarly  provided  \vith  dampers  and  heat,  as  pre- 
viously described  for  other  school  buildings. 

Sections  are  given  showing  cold-air  rooms,  indirect  radiators, 
mixing-dampers  and  fan. 

Plates  XXIX,  XXX,  XXXI  and  XXXII.— Perspective  and 
plans  for  an  eight-room  schoolhouse. 


THE    SCHOOL    HOUSE. 


167 


This  schoolhouse  is  in  the  city  of  New  Bedford,  C.  Hammond 
and  Sons  being  the  architects,  and  is  a  two-story  building  con- 
structed of  red  brick  with  granite  trimmings ;  the  roof  covered 
with  black  slate. 

It  contains  eight  class-rooms  and  two  teachers'  rooms,  also  wide 
corridors  and  vestibules.  In  the  basement  are  located  play  rooms 
and  sanitary  rooms  for  the  pupils,  a  room  for  the  janitor,  boiler 


PLATE   XXX. 


'BASEMENT  PLAN 


BROCK  AVE.,  SCHOOL, 

NEW    BEDFORD,  MASS..U.S f 


and  fuel  rooms,  together  with  fresh-air  chambers  and  the  indirect 
steam-heating  radiators  and  boilers. 

The  class-rooms  are  intended  to  accommodate  49  pupils  and 
teacher,  a  total  of  50.  They  are  well  lighted,  the  pupils'  seats  and 
desks  being  so  placed  that  the  light  is  received  from  the  left  and  rear. 

The  blackboards  are  of  best  black  slate. 

The  teachers'  rooms  in  the  second  story  are  provided  with  heat- 
ing radiators  and  toilet  closets. 

The  corridors  are  wide  and  well  lighted,  there  being  glass  in  the 
transoms  over  the  doors  and  a  large  panel  of  heavy  glass  in  each 
door  leading  from  the  class-rooms. 


168  THE    SCHOOL   HOUSE. 

The  walls  of  the  corridors,  staircase  wings  and  vestibules  are 
faced  with  selected  smooth-cut  brick.  The  vestibule  floors  are 
of  tiles. 

The  basement  floor  is  of  concrete,  well  rolled  and  smooth.  The 
plastering  is  of  Windsor  cement,  and  steel  lathing  is  used  on  ceil- 
ings and  wooden  partitions.  The  plastering  on  the  brick  walls  is 
laid  directly  on  the  brick. 

PLATE   XXXI. 


FIRST   FLOOR  PLAN.     BROCK  AVE..SCHOOL, 

NEW  BEDFORD,  MASS..U.S.A. 


The  partitions  around  the  stairways  are  provided  with  fire  stops, 
as  required  by  the  Massachusetts  building  regulations. 

The  conductors,  gutters  and  flashings  are  of  rolled  copper.  The 
inside  finish  of  the  first  and  second  stories  is  of  selected  red  oak, 
and  the  floors  double,  the  upper  floors  being  of  the  best  rift  yellow 
pine,  not  over  three  inches  wide. 

In  each  corridor  are  clothes  rails  with  bronzed  hooks  for  holding 
the  pupils'  clothing. 

Electric  call-bells  and  speaking-tubes  are  provided  from  each 
class-room  to  the  principal's  room,  also  to  the  janitor's  room,  and 
from  the  main  entrance  to  the  janitor's  room. 


THE    SCHOOL    HOUSE. 


169 


The  sanitary  closets  and  urinals  in  the  basement  are  provided 
with  automatic  flushing  tanks,  and  are  well  trapped  and  well 
ventilated  into  a  special  vent-flue  which  contains  steam-pipes,  to 
cause  an  outflow  of  foul  air  from  the  basement  rooms  and  sanitary 
fixtures. 

In  the  first  and  second  story  is  a  galvanized-iron  stand-pipe  and 
50  feet  of  hose  for  use  in  case  of  fire.  Suitable  hose  racks  are 
provided. 

PLATE   XXXII. 


SECOND   FLOOR    PLAN. 


BROCK  AVt.,  SCHOOL, 

NEW  BEDFORD,  MAS5«U.&A. 


In  the  basement,  corridors  and  teachers'  rooms  are  water  faucets 
and  basins  or  bowls  well  trapped. 

Two  horizontal  tubular  boilers  are  provided  for  heating  the 
building,  each  being  42  inches  in  diameter,  14  feet  long,  having 
38  tubes  three  inches  in  diameter  and  13  feet  long.  Each  boileriis 
rated  at  32  horse-power  and  tested  to  150  pounds  under  hydraulic 
pressure. 

Safety-valves,  automatic  damper-regulator,  steam-gauges,  water- 
gauges,  fusible  plugs,  blow-off  cocks  and  all  required  valves  are 
provided. 


170  THE    SCHOOL   HOUSE. 

A  supplementary  sectional  boiler  of  the  rated  capacity  of  400 
square  feet  is  also  provided  for  the  vent-shaft  heaters  and  for  use 
in  mild  weather  in  the  place  of  the  main  heating  boilers. 

The  piping  for  the  vent-shaft  heaters  is  so  arranged  that  either 
or  both  main  boilers  or  the  sectional  boiler  may  be  used  as  desired. 
The  piping  in  the  building  is  what  is  known  as  the  two-pipe 
system,  with  supply  and  return  for  each  radiator  or  coil,  and  so 
adjusted  that  water-hammer  or  snapping  is  prevented  during  the 
circulation  of  the  steam,  and  suitable  allowance  is  made  for  expan- 
sion and  contraction.  The  return  pipes  are  not  shown  on  the 
drawings,  but  generally  follow  the  line  of  the  supply  pipes. 

Valves  are  provided  by  which  part  or  the  whole  of  the  heating 
radiators  may  be  used  as  desired.  The  fresh  air  for  each  class- 
room is  warmed  by  being  passed  through  cast-iron  indirect 
radiators  in  the  basement.  Four  hundred  square  feet  of  indirect 
radiation  is  provided  for  each  class-room,  and  is  divided  into  three 
sections  or  stacks,  so  that  a  part  or  the  whole  may  be  used  as 
desired. 

In  the  teachers'  rooms  and  corridors  are  direct  radiators,  and  in 
the  basement  are  lines  of  steam-pipes  overhead.  Radiators  are 
also  provided  for  bringing  warm  air  up  through  two  registers  in 
the  floor  of  the  first-story  corridor,  the  air  being  rotated  from  the 
corridor  floor  near  the  stairway  extensions.  These  are  designated 
as  foot-warmers,  and  enable  the  pupils  to  warm  their  feet  and  hands 
and  dry  their  clothing  in  cold,  stormy  weather. 

In  the  floor  of  the  closets  between  the  class-rooms  in  the  first 
story  are  what  are  termed  rotating  registers,  for  use  at  night  or 
when  the  rooms  are  not  in  use.  The  windows  in  the  cold-air 
rooms  and  the  dampers  in  the  vent -flues  being  closed,  the  rotating 
registers  are  opened  and  air  is  drawn  down  from  the  class-rooms, 
passes  through  the  indirect  radiators  and  is  returned  to  the  class- 
rooms through  the  warm-air  flues,  thereby  keeping  the  rooms  warm 
and  saving  fuel. 

The  warm  fresh  air  is  brought  into  the  class-rooms  through 
openings  eight  feet  above  the  floor  as  shown  in  the  drawings,  and 
the  vitiated  air  is  removed  through  openings  at  the  floor  level, 
located  as  shown  in  the  plans.  The  warm-air  and  foul-air  flues  are 
of  brick,  and  well  smoothed  up  on  the  inside. 

Each  foul-air  flue  contains  20  square  feet  of  steam-pipe  heating 
surface  for  causing  an  outward  flow  of  vitiated  air,  and  is  also 
provided  with  a  curved  damper  of  galvanized  iron,  operated  by  a 
chain  and  catch,  by  which  the  amount  of  air  taken  from  the  rooms 


THE    SCHOOL    HOUSE.  171 

can  be  regulated  or  shut  off  when  the  rooms  are  not  in  use.  In 
each  warm-air  flue  is  a  galvanized-iron  mixing-valve. 

There  is  also  an  adjusting  damper  by  which  the  supply  of  fresh 
w^arm  air  to  each  room  may  be  regulated  or  shut  off  if  any  room  is 
not  occupied. 

The  direct  radiation  consists  of  vertical  loop  cast-iron  radiators 
of  an  aggregate  of  325  square  feet  of  surface  in  corridors  and 
teachers'  rooms,  and  280  square  feet  of  surface  of  J  J  inch  steam- 
pipe  in  coils  overhead,  in  the  basement. 

The  indirect  radiators  for  the  foot-warmers  consist  of  100  square 
feet  each  of  cast-iron  radiators. 

At  an  inspection  of  this  building  the  following  conditions  were 
found : 

Weather,  fair ;  wind  north  and  moderate ;  outside  temperature, 
21°  F. ;  outside  relative  humidity,  57  per  cent;  barometer,  30.32; 
average  temperature  of  air  at  inlets  to  class-rooms,  87.1°  F. ;  average 
supply  of  fresh  air  through  inlet  to  each  class-room,  in  cubic  feet 
per  minute,  2,337;  average  amount  of  air  removed  at  outlet  from 
each  class-room,  in  cubic  feet  per  minute,  2,984;  average  amount 
of  air,  in  cubic  feet  per  minute,  supplied  at  inlet  for  seating 
capacity  of  each  class-room,  47.7 ;  average  amount  of  air,  in  cubic 
feet  per  minute,  removed  through  outlet  in  class-rooms,  for  each 
pupil,  60.9 ;  greatest  amount  of  air,  in  cubic  feet  per  minute, 
supplied  at  inlet  to  any  class-room,  3,247;  least  amount,  1,730 
cubic  feet ;  average  difference  in  temperature  in  any  room,  taken  at 
the  same  time  at  four  places,  at  the  breathing  plane,  2°  F. ;  least 
difference  at  same  points,  .5°  F. ;  average  temperature  at  teachers' 
desks,  69.5°  F.  No  uncomfortable  drafts  could  be  perceived  in 
the  several  rooms. 

Plates  XXXIII,  XXXIV  and  XXXV.— Plans  for  a  small  high  or 
a  grammar  school  —  a  two-story  building  constructed  of  yellow 
brick,  with  yellow  terra-cotta  trimmings  and  slated  roof.  If  used 
as  a  grammar  school  the  rooms  intended  for  the  chemical  and 
physical  laboratories  can  be  used  as  class-rooms. 

In  the  first  story  are  four  class,  two  recitation,  and  two  teachers' 
rooms,  with  toilets  connected. 

The  corner  rooms  are  28  by  32  feet  and  12  feet  high,  intended 
for  forty -nine  pupils.  The  recitation  rooms  are  each  17  feet 
8  inches  by  28  feet. 

The  teachers'  rooms,  including  toilets,  are  each  11  feet  4  inches 
by  28  feet.  The  center  corridor  is  15  feet  and  the  front  corridor 
12  feet  wide. 


172 


THE    SCHOOL    HOUSE. 


THE    SCHOOL   HOUSE. 


173 


174 


THE   SCHOOL   HOUSE. 


THE    SCHOOL   HOUSE.  175 

In  the  second  story  are  two  class-rooms,  a  chemical  and  a  physi- 
cal laboratory,  each  28  by  32  feet  by  12  feet  high,  an  assembly 
hall  36  by  73  feet,  and  two  storage-rooms  in  the  stairway  exten- 
sion. The  stairways  at  each  end  of  the  building  are  six  feet  wide 
and  railed  on  both  sides.  The  main  doors  open  both  ways,  as  do 
also  the  assembly-room  doors. 

In  the  basement,  which  is  12  feet  high,  except  the  boiler-room, 
which  is  14  feet  6  inches  in  height,  is  a  manual -training  room, 
a  boys'  and  a  girls'  recreation-room,  sanitary  rooms,  boiler-room  and 
coal -room,  cold-air  rooms  and  places  for  bicycles.  Two  stairways 
lead  up  to  the  first  story  and  there  are  two  doors  from  the  outside 
to  the  stairway  extension. 

The  basement  floor  is  of  concrete,  with  a  covering  of  Portland 
cement  or  rock  asphalt. 

The  interior  walls  and  partitions  are  of  brick,  except  between 
the  two  recitation-rooms,  on  the  corridor  sides  of  the  teachers' 
rooms,  and  the  small  storage-rooms  in  the  second  story.  Between 
the  rooms  are  closets  with  doors  connecting  with  the  class-rooms. 
All  wooden  partitions  are  lathed  with  expanded  metal  lathing, 
which  is  the  only  kind  of  lathing  used  throughout  the  building. 
Fire  stops,  which  are  required  by  the  Massachusetts  building  laws 
in  all  school  buildings,  are  also  built. 

The  walls  of  the  corridors  and  stairway  extensions  have  a  face 
of  good  quality  smooth  brick,  well  laid  and  painted  with  light 
colored  gloss  paint  but  with  no  wood  finish. 

Bookcases  with  glass  doors  are  placed  in  each  class-room  between 
the  heat  and  the  vent-flues. 

The  windows  in  the  first  and  second  story  rooms  have  a  double 
run  of  sash ;  the  basement,  stairway  extension  and  corridor  win- 
dows, single.  The  windows  between  the  corridors  and  rooms  are 
six  feet  above  the  floor,  and  each  door,  except  to  the  store-rooms  and 
teachers'  rooms,  has  a  center  panel  of  heavy  glass.  There  are 
windows  over  the  doors  leading  to  the  front  and  end  entrances. 
All  inside  doors  have  glass  transoms. 

The  corridors  in  which  clothing  is  to  be  hung  have  wooden 
hanging  frames  projecting  one  foot  from  the  sides,  with  two  pieces 
for  hooks,  the  lower  one  nearest  the  wall  and  the  upper  one  project- 
ing, with  hooks  alternating,  to  prevent  the  crowding  of  the  clothing. 

In  the  basement  of  the  stairwray  extensions  are  stands  for  bicycles, 
which  are  to  be  brought  down  a  runway  by  the  side  of  the  base- 
ment steps.  Gymnastic  appliances  are  supplied  in  both  boys'  and 
girls'  recreation  rooms. 


176  THE    SCHOOL    HOUSE. 

The  manual-training  room  is  fitted  with  lathes,  grindstone, 
work -benches  and  tools. 

The  chemical  laboratory  has  tables,  sinks,  chemical  closets  with 
glass  sliding  doors,  water,  illuminating  gas,  electric  power  and  the 
requisite  apparatus.  The  physical  laboratory  is  also  supplied  with 
the  necessary  tables  and  apparatus. 

The  assembly  hall  has  two  large  ceiling  lights,  connecting  with 
skylights  in  the  roof.  The  ceiling  lights  are  fitted  with  roller-shade 
curtains.  One  of  the  ceiling  lights  and  one  skylight  has  a  hinged 
section  operated  by  chains  and  pulleys,  which  can  be  used  for  ven- 
tilation should  the  room  become  overheated  in  moderate  weather. 

The  building  is  heated  by  a  low-pressure,  two-pipe,  gravity, 
steam  system,  with  two  horizontal  tubular  boilers,  each  54  inches 
in  diameter,  15  feet  3  inches  long,  containing  60  three-inch  tubes 
14  feet  long;  also  by  a  smaller  horizontal  tubular  boiler,  36  inches 
in  diameter,  9  feet  3  inches  long,  containing  34  two-and-one-half- 
inch  tubes,  8  feet  long.  This  small  boiler  is  intended  to  furnish 
steam  for  the  steam-pipes  in  the  vent-ducts  and  for  a  low-pressure 
engine  to  run  the  turning  lathes,  etc.,  in  the  manual -training  room 
when  the  large  boilers  are  not  in  use.  It  can  also  be  used  to  warm 
the  radiators  in  the  spring  and  fall  months,  When  but  very  little 
heat  is  required  for  a  part  of  the  day.  The  three  boilers  are  set, 
piped,  valved  and  connected  so  that  either  may  be  used  as  desired. 
When  it  is  necessary  to  use  very  low  pressure  in  the  larger  boilers  for 
warming  the  building  in  moderate  weather,  the  small  boiler  can  be 
used  at  higher  pressure  to  run  the  engine  for  operating  the  lathes  and 
also  for  heating  the  vent-flues.*  A  reducing  pressure-valve  should 
be  provided,  also  a  separator,  tank,  pump,  and  pump  governor. 

If  an  electric  motor  is  used  for  running  the  lathes,  it  will  not  be 
necessary  to  use  the  pump,  etc.,  the  small  boiler  can  be  reduced 
in  size  and  the  system  can  be  run  by  gravity  return.  This  would 
be  advisable  where  electric  power  is  to  be  had. 

By  having  the  boiler-room  lower  than  the  other  parts  of  the 
basement  a  good  return  of  water  by  gravity  to  the  boiler  is  secured, 
and  a  complicated  system  of  traps,  pumps,  etc.,  is  rendered 
unnecessary.  The  supply  and  return  pipes  are  of  ample  size, 
properly  pitched,  graded,  dripped  and  valved,  so  as  to  secure  a  free 
and  noiseless  circulation  and  return  to  the  boilers. 

The  class-rooms,  assembly  hall,  recitation  rooms,  laboratories 
and  teachers'  rooms  are  heated  by  stacks  of  indirect  radiators  of 
the  H.  B.  Smith  School  Pin,  Bundy  Newport,  American  Sterling, 
or  similar  pattern,  placed  in  the  cold-air  rooms  in  the  basement ; 


THE    SCHOOL    HOUSE.  177 

each  stack  being  divided  into  three  sections  so  that  part  or  the 
whole  may  be  used  as  desired. 

Direct  radiation  is  supplied  in  the  corridor  and  stair  extensions, 
and  two  lines  of  one-and-one-quarter  inch  steam-pipe  under  the 
clothing  racks  in  the  corridors  for  drying  in  stormy  weather  and 
for  heating  in  extremely  cold  weather. 

At  each  end  of  the  lower  corridor  there  are  floor  registers  without 
valves  for  use  as  foot-warmers,  the  air  being  drawn  down  through 
the  register  nearest  the  door,  passing  through  the  stack  of  radiators, 
which  are  to  be  cased  with  galvanized  iron  and  suspended  from 
the  basement  ceiling,  and  coming  up  through  the  register  farthest 
from  the  door.  Good  exhaust  flues  are  provided  from  the  corridors, 
and  the  leakage  of  air  into  the  corridors  is  sufficient  to  keep  them 
in  good  condition. 

In  the  chemical  and  physical  laboratories  four  lines  of  one-and- 
one-quarter-inch  steam-pipe  should  be  placed  on  the  two  exposed 
sides,  to  be  used  at  night  to  prevent  freezing  in  extremely  cold 
weather  when  the  rooms  are  not  in  use. 

Direct  radiation  is  placed  in  the  assembly  hall  in  addition  to  the 
indirect,  to  keep  the  room  partly  warmed  and  to  heat  quickly  when 
the  indirect  is  turned  on  before  the  room  is  occupied.  When 
occupied  the  direct  should  be  shut  off  and  only  the  indirect  used. 

The  manual-training  room  in  the  basement  is  also  supplied  with 
direct  and  indirect  radiation.  The  recreation  rooms  and  sanitary 
rooms  are  warmed  by  lines  of  overhead  steam-pipes,  the  supply 
mains  in  the  basement  being  protected  by  non-heat-conducting  pipe 
covering. 

The  ceiling  of  the  boiler-room  and  the  cold-air  rooms  are 
specially  protected  by  non-heat-conducting  material  placed  betwreen 
the  flooring  and  the  metallic  lathing  —  in  the  case  of  the  boiler- 
room,  to  prevent  the  heat  passing  up  through  the  floor  and  over- 
heating the  rooms  above,  which  often  happens  when  the  boilers 
are  located  under  the  school-room  and  no  protection  is  provided 
other  than  the  wooden  floors.  It  is  advisable  to  construct  the  ceil- 
ing of  iron  beams  and  terra-cotta  arches  and  make  the  boiler-room 
fire-proof . 

If  the  cold-air  rooms  are  not  protected  overhead  the  cold  air 
chills  the  floor  directly  over  them,  sometimes  to  an  uncomfortable 
degree  in  extremely  cold  weather.  The  cold-air  room  windows 
should  be  hung  in  two  parts  and  be  provided  with  cords  and  pulleys 
for  opening  and  closing. 


178  THE    SCHOOL   HOUSE. 

The  fresh  warm  air  is  taken  into  the  rooms  through  inlets  of  the 
same  size  and  location  as  previously  described  in  other  plans. 

The  dimensions  of  each  of  the  four  warm-air  flues  for  the 
assembly  hall  are  52  by  24  inches. 

Tests  of  the  best  work  show  that  by  having  the  warm-air  flues 
of  liberal  size  the  air  is  introduced  into  the  rooms  at  a  lower  velocity 
and  temperature  than  when  the  flues  are  too  small.  In  moderate 
weather  this  is  a  decided  advantage,  as  a  sufficient  amount  of  fresh 
air  can  be  supplied  without  overheating  the  room,  as  was  the  case 
in  some  of  the  earlier  work,  where  the  temperature  had  to  be  raised 
too  high  for  comfort  in  order  to  obtain  the  required  volume  of  air 
with  small  ducts. 

In  some  cases,  especially  where  fans  or  blowers  have  been  used, 
the  ducts  have  been  reduced  in  size  under  pretense  of  cheapening 
the  cost  of  construction,  and  the  air  forced  into  the  room  at  a  high 
velocity,  causing  uncomfortable  drafts  and  a  needless  expenditure 
of  power. 

Wire  grills  are  used  instead  of  cast-iron  registers  to  cover  the 
inlets  and  outlets.  Mixing  valves  are  supplied  for  warm-air  flues. 
Adjustable  galvanized-iron  cut-offs  or  adjusting  dampers  are  pro- 
vided at  the  bottom  entrance  for  the  warm  air  to  regulate  the  supply 
of  air  to  the  several  rooms  under  the  varying  conditions  of  wind  and 
temperature  or  to  cut  off  the  supply  from  any  unoccupied  room. 

The  use  of  double  windows  will  be  of  great  service  in  very  cold 
and  windy  weather,  and  will  to  a  considerable  extent  prevent  too 
rapid  cooling  and  precipitation  of  the  air  by  the  glass  surface 
which  often  causes  downward  drafts  in  front  of  single  windows. 
A  considerable  saving  of  fuel  can  be  made  by  using  double 
windows. 

The  openings  from  the  rooms  and  corridors  into  the  vent -flues 
are  of  the  size  and  location  previously  described  in  other  plans. 
Galvanized-iron  dampers  are  also  provided  for  these  vent  openings. 
Vent-flue  heaters  are  installed. 

By  the  use  of  steam-pipes  or  radiators  in  the  vent -flues  a  good 
velocity  is  given  to  the  outgoing  foul  air,  back  draft  is  prevented 
without  the  use  of  flap-valves,  whose  chief  purpose  appears  to  be 
to  obstruct  the  outflow  of  the  foul  air  and  to  cause  a  disagreeable 
noise  by  flapping  up  and  down  when  moved  by  the  wind. 

Experience  and  not  theory  has  taught  that  means  should  always 
be  provided  for  causing  an  outflow  of  the  foul  air  through  the  vent- 
flues  and  ducts,  either  by  heat  or  mechanical  means.  Attempts  to 
cause  an  outflow  by  other  methods,  especially  when  the  outlets  are 


THE   SCHOOL    HOUSE.  179 

obstructed  by  worse  than  useless  flexible  valves,  which  are  liable 
to  close  when  the  room  is  occupied  and  ventilation  required,  and  to 
open  when  the  room  is  unoccupied  and  no  ventilation  needed, 
usually  result  in  noticeable  failures,  as  proved  by  numerous  tests. 

With  these  contrivances  there  appears  to  be  no  practicable  way_ 
of  adjusting  the  outflow,  and  in  extremely  cold  and  windy  weather, 
when  the  outflow  will  need  checking,  the  flap-valves  will  be  open 
to  their  full  capacity ;   but  in  mild  and  calm  weather,  when  they 
should  be  wide  open,  they  are  liable  to  be  closed. 

The  sanitary  closets  are  of  a  pattern  having  an  especially  large 
local  vent  (four  inches  in  diameter)  and  each  closet  is  vented  into 
an  underground  duct  running  to  the  smoke-flue  surrounding  the 
iron  smoke-pipe  from  the  boilers. 

Each  closet  has  an  automatic  flush.  The  divisions  or  par- 
titions between  the  closets  are  raised  eight  inches  above  the  floor 
on  metal  standards,  which  allows  the  janitor  to  use  water  liber- 
ally for  washing  the  floor  through  a  hose  furnished  for  that 
purpose. 

Each  line  of  closets  is  connected  with  a  well-vented  and  trapped 
soil-pipe. 

The  urinals  are  fitted  with  a  perforated  flushing-pipe,  and  have 
a  liberal  vent  connected  with  the  main  closet  vent-duct.  The 
discharge  pipe  should  be  well  trapped  and  vented. 

The  sanitary -rooms  are  ventilated  through  the  closets  and  urinals 
to  the  space  around  the  boiler  smoke-pipe. 

All  plumbing  should  be  of  the  open  or  exposed  pattern  and  all 
fixtures  well  trapped  and  vented. 

Plates  XXXVIII  and  XXXIX  are  designs  by  the  late  John  T. 
White,  the  friend  and  companion  inspector  of  the  writer  for 
eighteen  years. 

Plate  XXXVIII. — Design  for  a  direct -indirect  radiator. 

This  radiator  is  designed  to  be  used  in  small  halls  or  in  churches, 
where  it  may  be  easy  to  provide  for  a  strong  exhaust  leg  of  a  venti- 
lating system,  but  difficult  to  arrange  for  a  straight  indirect  method 
of  heating  and  supplying  air. 

Almost  any  good  direct  radiator  may  be  used  or  a  coil  of  pipe. 

The  radiator  is  first  cased  in  metal,  and  may  then  be  finished  in 
wood  in  any  way  desired. 

The  fresh-air  opening  has  an  area  of  two  square  inches  for  each 
square  foot  of  radiation ;  but  the  supply  of  air  from  outside  may  be 
controlled  by  damper,  as  shown,  which  can  be  held  in  any  position. 
The  inside  damper  is  always  to  be  entirely  open  or  shut.  When 


180 


THE    SCHOOL    HOUSE. 


THE    SCHOOL    HOUSE. 


181 


open,  the  air  is  taken  from  the  room,  and  the  effect  is,  of  course, 
nearly  the  same  as  with  a  direct  radiator. 

Such  a  radiator  with  100  square  feet  of  surface  has  been  found 
to  furnish  500  cubic  feet  of  air  per  minute  under  fairly  favorable 
conditions. 

PLATE   XXXVII. 


I  I 


-,  JL  Jl       ill 


BOY5' 


TtACHERS 


P 


Q|RL5- 


U   UL 


_______ 


BOARD 
TEhCE 


5AfSJTARY     BUILDING 


The  fresh-air  opening,  extending  nearly  the  entire  length  of  the 
stack,  gives  a  more  even  distribution  of  air  to  the  heating  surface 
than  (as  is  generally  the  case)  where  the  opening  is  near  the  center 
of  the  stack  and  the  area  is  obtained  by  one  which  is  high  and  short 
instead  of  low  and  long,  as  shown  in  this  design. 


182 


THE    SCHOOL    HOUSE. 


PLATE   XXXVIII. 


DAM  PER  CONTROLLER. 


SECTION 


HOOD 


PLA  N 


SCALE 

]~T  1    \    ]    J_j_JL 

ONE  FOOT 

DESIGN  FOR.  DIRECT-INDIRECT  RADIATOR. 


THE    SCHOOL    HOUSE. 


183 


Plate  XXXIX. — Design  for  setting  a  portable  furnace,  showing 
a  method  of  setting  a  portable  furnace  in  a  small  hall  or  in  a 
church,  where  the  registers  are  necessarily  placed  in  the  floor. 


PLATE   XXXIX. 


FURNACE  - 


In  such  cases,  when  the  room  is  too  warm,  the  usual  remedy  is 
to  close  the  register  and  thus  shut  off  the  supply  of  air,  throwing 
all  the  heat  back  on  the  furnace,  increasing  the  danger  from  fire 
and  possible  injury  to  the  pipes  and  castings.  The  registers  here 
shown  have  no  valves,  and  the  temperature  of  the  incoming  air  is 
regulated  by  a  mixing-valve  in  each  duct  as  shown. 


184 


THE    SCHOOL    HOUSE. 


There  is  a  damper  for  controlling  the  supply  of  outside  air,  and 
a  rotating  damper  is  provided. 

The  cold-air  and  warm-air  ducts  are  much  larger  than  those 
generally  installed. 

There  is  a  pit  under  the  furnace  about  two  feet  deep — an 
essential  feature  for  good  work. 

If  any  small  rooms  are  to  be  heated,  branches  can  be  taken  from 
the  large  pipes  with  switch  dampers  to  control  the  flow  of  air. 

PLATE   XL. 


CORRIDOR      FOOT- WARMER 


Plate  XL. — Foot -warmers  to  be  placed  in  schoolhouse  corridors. 

Six  sections  of  indirect  cast-iron  pin  radiators  are  made  into  a 
stack  containing  120  square  feet  of  radiating  surface,  which  is 
suspended  below  the  basement  ceiling  on  two  1^-inch  iron  pipes, 
which  are  secured  to  the  floor  timbers  above  by  iron  hangers. 
The  sections  are  15 J  inches  high  at  their  highest  part  and 
36  inches  long. 

The  pins  are  one  inch  long  and  the  sections  are  set  up  four  inches 
on  centers  with  one-half  inch  space  between  the  ends  of  the  pins. 

Two-inch  right-and-left  nipples  are  used  for  connecting  the 
sections,  which  are  tapped  for  two-inch  supply  and  return.  A 
f-inch  air-valve  is  placed  in  the  quarter-turn  or  elbow  of  the 
return.  This  air-valve  is  placed  in  a  position,  where,  should  it  be 
desirable  to  moisten  the  air,  a  small  quantity  of  steam  may  be 
allowed  to  escape  through  the  air-valve. 


THE    SCHOOL    HOUSE.       .  185 

The  casing  is  of  twenty-four  gauge  galvanized  iron  put  together 
with  screws,  nuts  and  angle  iron,  so  that  it  may  be  easily  removed 
should  it  be  required  to  make  repairs  on  the  heating-stack.  In  the 
bottom  of  the  casing  are  two  clean-out  slides  for  removing  any 
dirt  or  substance  that  may  fall  through  the  register  gratings  in  the 
floor  of  the  corridor. 

The  air  is  taken  from  the  corridor  down  on  one  side,  passes 
under  and  up  through  the  radiator-stack  and  ascends  to  the  corridor 
through  another  register  in  the  corridor  floor. 

This  arrangement  prevents  the  accumulation  of  dirt  and  various 
substances  that  would  fall  on  the  heated  radiators  through  a  register 
placed  directly  above  the  heating  stack. 

COVERING  BOILERS. 

Covering  boilers  by  the  use  of  sand  is  not  advisable,  because  if 
cracks  appear  in  the  setting,  the  sand  will  deposit  in  the  cracks 
when  the  wall  is  heated  and  will  continue  to  do  so  and  widen  the 
cracks. 

When  a  boiler  is  arched  over  with  bricks,  care  should  be  taken 
that  the  arch  does  not  rest  on  the  boiler,  and  that  at  least  an  inch 
space  is  left  between  the  boiler  and  the  brick  arch,  which  should 
be  self-supporting. 

An  eighty-five  per  cent  magnesia  covering  when  properly  applied 
makes  a  very  desirable  non-heat-conducting  protection  over  the 
boiler  and  gives  very  satisfactory  results. 

The  practice  of  leaving  a  space  completely  bricked  in  around  the 
boiler  to  gain  additional  heating  surface  is  now  but  seldom  resorted 
to,  as  the  tendency  is  to  burn  out  that  part  of  the  boiler  above  the 
water  line.  The  returning  of  hot  gases  from  the  uptake,  across 
the  top  of  the  boiler  is  another  defect,  as  its  efficiency  is  of  doubt- 
ful value. 

Another  practice  not  to  be  recommended,  is  that  of  continuing 
the  boiler  walls  above  the  boiler  for  the  purpose  of  obtaining 
a  space  above  the  boiler  for  heating  air  for  ventilation,  by  utilizing 
the  heat  escaping  through  the  boiler  covering.  Should  cracks  be 
made  in  the  setting  or  covering,  there  is  danger  of  the  unconsumed 
gases  passing  into  and  contaminating  the  air  intended  for  ven- 
tilation. 

With  this  setting  the  fireman  or  engineer  is  obliged  to  crawl 
through  a  door  and  over  the  boiler  to  reach  either  the  steam  or 
safety-valve,  and  in  case  of  the  safety-valve  blowing  off  to  relieve 
too  high  pressure,  the  steam  is  carried  by  the  wrarm  air  ducts  into 


OF  THE "> 


UNIVERSITY 


186 


THE    SCHOOL    HOUSE. 


the  -school  or  other  rooms  which  receive  their  air  from  this  source, 
and  possibly  causing  excitement  or  a  panic  among  the  pupils. 

Plates  XLI,  XLII,  XLIII  and  XLIV.  — Settings  for  horizontal 
tubular  boilers.  Designed  and  recommended  by  the  Hartford 
Boiler  Inspection  and  Insurance  Company. 


THE    SCHOOL   HOUSE. 


187 


188 


THE    SCHOOL   HOUSE. 


PLATE  XLIII. 


CROSS  SECTION  OF  SETTING  FOR  ONE  HORIZONTAL  TUBULAR  BOILER. 


THE   SCHOOL   HOUSE, 


189 


TABLE    15.     (APPROXIMATE)   AREAS 


Inches 

10 

11 

12 

13 

14 

15 

16 

17 

18 

19 

20 

21 

22 

23 

24 

25 

26 

10 

69 

.76 

.83 

.9 

.97 

104 

1  11 

1  18 

1  25 

131 

1  38 

1  45 

1.52 

1.59 

1  66 

1  73 

1  8 

11 

12 

.76 

83 

.84 
.91 

.91 
1 

.99 
1.08 

1.06 
1  16 

1.14 
1  25 

1.22 
1  33 

1.29 
1  41 

1.37 
1  5 

1.45 
1  57 

1.52 
1  66 

1.6 
1  75 

1.68 
1  83 

1.75 
1  91 

1.83 
2. 

1.9 

208 

1.98 
9,  16 

13 
14 
15 

.9 
.97 
104 

.99 
1.06 
1.14 

1.08 
1.16 
1.25 

,1.17 
1.26 
1  35 

1.26 
1,36 
1  47 

1.35 
1.47 
1.56 

1.44 
1.55 
166 

1.53 
1.65 
1.77 

1.62 
'1.75 

1.87 

1.71 

1.84 
1  97 

1.8 
1.94 

208 

1.89 
2.04 
2.18 

1.98 
2.13 
2.29 

2.07 
2.23 
2.39 

2.16 
2.33 
2.5 

2.25 
2.43 
2.6 

2.34 
2.52 

2.7 

16 

1.11 

1.22 

1.33 

1.44 

1.55 

1.66 

1.77 

.1.88 

"2V" 

2.1.1 

2.22 

2.33 

2.44 

2.55 

2.66 

2.77 

2.88 

17 

1.18 

1.29 

1.41 

1.53 

1.65 

1.77 

1.88 

2. 

2.12 

2.24 

2.36 

2.47 

2.59 

2.71 

2.83 

2.95 

3.07 

18 

1.25 

1.37 

1.5 

1.62 

1.75 

1.87 

2. 

2.12 

2.25 

2.37 

2.5 

2.62 

2.75 

2.87 

3. 

3.12 

3.25 

19 

1.31 

1.45 

1.57 

1.71 

1.84 

1,97 

2.11 

2.24 

2.37 

2.5 

2.63 

2.77 

2.9 

3.03 

3.16 

3.29 

3.43 

20 

1.38 

1,£2 

1.66 

1.8 

1.94 

2.08 

2.22 

2.36 

2.5 

2.63 

2.77 

2.91 

3.05 

3.19 

3.33 

3.47 

3.61 

21 

1.45 

1.6? 

1.75 

1.89 

2.04 

2.18 

2.33 

2.47 

2.62 

2.77 

2.91 

3.06 

3.2 

3.35 

3.5 

3.64 

3.7 

22 

1.52 

1.68 

1.83 

1.98 

2.13 

2.29 

2.44 

2.59 

2.75 

2.9. 

3.05 

3.2 

3.36 

3.51 

3.66 

3.81 

3.97 

23 

1.59 

1.75 

1.91 

2.07 

2.23 

2.39 

2.55 

2^71. 

£$7 

3,03 

3.19 

3.35 

3.51 

3.67 

3.83 

3.99 

4.15 

24 

1.66 

l".83 

2. 

2.16 

2.33 

2.5 

2.66 

2.83 

3. 

3.16 

3.33 

3.5 

3.66 

3.83 

4. 

4.16 

4.33 

25 

1.73 

1.9 

.2.08 

2.25 

2.43 

2.6 

:'2.77 

2.915 

3J2 

3.29 

3.47 

3.64 

3.81 

3.99 

4.16 

4.34 

4.51 

26 

1.8 

r.98 

2.16 

2.34 

2^52 

•217 

2.8 

3.07 

3.25 

3.43 

.3.61 

3.7 

3.97 

4.15 

4.33 

4.51 

4.69 

27 

1.87 

2.'06 

2.25 

2.43 

2.62 

2.81 

3. 

3.18 

3.33 

3.56 

3.75 

3.93 

4.12 

4.31 

4.5 

4.68 

4.87 

28 

1.94 

2,13 

2.33 

2.52 

2;72 

2.91 

3.11 

3.3 

3.5 

3.69 

3.88 

4.08 

4.27 

4.47 

4.66 

4.86 

5.05 

29 

2.01 

2M 

2.4 

2.61 

2.81^ 

3. 

3.22 

3.42 

3.62 

3.82 

4.02 

4.22 

4.43 

4.63 

4.83 

5.03 

5.23 

30 

2.08 

2$9 

2.5 

2.7 

]2.9 

3.12 

3.33 

3.54 

3.75 

3.95 

4.16 

4.37 

4.58 

4.79 

5. 

5.2 

5.41 

31 

2.15 

2:36 

2.58 

2.79 

3.01 

:3.$2 

;3.44 

3.66 

3.87 

4.09 

4.3 

4.52 

4.73 

4.95 

5.16 

5.38 

5.45 

32 

2.22 

2.44 

2.66 

2.88 

3.11 

3.33 

3.55 

.  .3.77 

•'&; 

4.22 

4.44 

4.66 

4.88 

5.11 

5.33 

5.55 

5.77 

33 

2.29 

2.52 

2.75 

2.9? 

3.2 

3.43 

3.66 

:3$£ 

4.12 

4.35 

4.58 

4.81 

5.04 

5.27 

5.5 

5.72 

5.95 

34 

2.36 

2.59 

2.83 

3.06 

3.3 

3.54 

3.77 

4. 

4.25 

4.48 

4.72 

4.95 

5.19 

5.43 

5.66 

5.9 

6.13 

35 

2.43 

2.67 

2.91 

3.15 

3.4 

3.64 

3.88 

4.13 

4.37 

4.61 

4.86 

5.1 

5.34 

5.59 

5.83 

6.07 

6.31 

36 

2.5 

2.75 

3. 

3.25 

3.5 

3.75 

4. 

4.25 

4.5 

4.75 

5. 

5.25 

5.5 

5.75 

6. 

6.25 

6.5 

37 

2.56 

2.82 

3.08 

3.34 

3.59 

3.85 

4.11 

4.36 

4.62 

4.88 

5.13 

5.39 

5.65 

5.9 

6.16 

6.42 

6.68 

38 

2.63 

2.9 

3.16 

3.43 

3.69 

3.95 

4.22 

4.48 

4.75 

5.01 

5.27 

5.54 

5.8 

6.06 

6.33 

6.59 

6.86 

39 

2.7 

2.97 

3.25 

3.52 

3.79 

4.06 

4.34 

4.6 

4.87 

5.14 

5.41 

5.68 

5.95 

6.22 

6.5 

6.77 

7.04 

40 

2.77 

3.05 

3.33 

3.61 

3.88 

4.16 

4.44 

4.72 

5. 

5.27 

5.55 

5.83 

6.11 

6.38 

6.66 

6.94 

7.22 

41 

2.84 

3.13 

3.41 

3.7 

3.98 

4.27 

4.55 

4.84 

5.12 

5.4 

5.69 

5.97 

6.26 

6.54 

6.83 

7.11 

7.4 

42 

2.91 

3.2 

3.5 

3.79 

4.08 

4.37 

4.66 

4.95 

5.25 

5.54 

5.83 

6.12 

6.41 

6.7 

7. 

7.29 

7.58 

43 

2.98 

3.28 

3.58 

3.88 

4.18 

4.47 

4.77 

5.07 

5.37 

5.67 

5.97 

6.29 

6.56 

6.86 

7.16 

7.46 

7.76 

44 

3.05 

3.36 

3.66 

3.97 

4.27 

4.58 

4.88 

5.19 

5.5 

5.8 

6.11 

6.41 

6.72 

7.02 

7.33 

7.63 

7.94 

45 

3.12 

3.43 

3.75 

4.06 

4.37 

4.68 

5. 

5.31 

5.62 

5.93 

6.25 

6.56 

6.87 

7.18 

7.5 

7.81 

8.12 

DIMENSIONS   IN  INCHES. 


AREAS   IN   SQUARE   FEET. 


OF    RECTANGULAR    OPENINGS. 


!^8 

29 

30 

31 

32 

33 

34 

35 

36 

37 

38 

39 

40 

41 

42 

43 

44 

45 

Inches 

!94 

2.01 

2.08 

2.15 

2.22 

2.29 

2.36 

2.43 

2.5 

2.56 

2.63 

2.7 

2.77 

2.84 

2.91 

2.98 

3.05 

3.12 

10 

13 

2.21 

2.29 

2.36 

2.44 

2.52 

2.59 

2.67 

2.75 

2.82 

2.9 

2.97 

3.05 

3.13 

3.2 

3.28 

3.36 

3.43 

11 

.33 

2.4 

2.5 

2.58 

2.66 

2.75 

2.83 

2.91 

3. 

3.08 

•  3.16 

3.25 

3.33 

3.41 

3.5 

3.58 

3.66 

3.75 

12 

.52 

261 

2  7 

2.79 

288 

2.97 

3.06 

3  15 

3.25 

3.34 

3.43 

3.52 

3.61 

37 

3.79 

3H8 

-5.97 

406 

13 

79 

?81 

2.9 

301 

311 

£J 

33 

3.4 

8.5 

3  59 

369 

379 

388 

398 

408 

4  18 

427 

4.37 

14 

.91 

3 

3.12 

3?,? 

3  33 

343 

354 

364 

375 

385 

3.95 

4.06 

4.16 

427 

4.3" 

4.47 

4.58 

4.68 

15 

.11 

3.22 

3.33 

3.44 

3.55 

3.66 

3.77 

3.88 

4. 

4.11 

4.22 

4.34 

4.44 

4.55 

4.66 

4.77 

4.88 

5. 

16 

.3 

3.42 

3.54 

3.66 

3,77 

3.89 

4. 

4.13 

4.25 

4.36 

4.48 

4.6 

4.72 

4.84 

4.95 

5.07 

5.19 

5.31 

17 

.5 

3.62 

3.75 

3.87 

4. 

4.12 

4.25 

,4.37 

4.5 

4.62 

4.75 

4.87 

5. 

5.12 

5.25 

5.37 

5.5 

5.62 

18 

.69 

3.82 

3.95 

4.09 

4.22 

4.35 

4.48 

4.61 

4.75 

4.88 

5.01 

5.14 

5.27 

5.4 

5.54 

5.67 

5.8 

5.93 

19 

.88 

4.02 

4.16 

4.3 

4.44 

4.58 

4.72 

:  4.86 

5. 

5.13 

5.27 

5.41 

5.55 

5.69 

5.83 

5.97 

6.11 

6.25 

20 

.08 

4.22 

4.37 

4.52 

4.66 

4.81 

4.95 

i  5.1 

5.25 

5.39 

5.54 

5.68 

5.83 

5.97 

6.12 

6.29 

6.41 

6.56 

21 

.27 

4.43 

4.58 

4.73 

4.88 

5.04 

5.19 

:  5.34 

5.5 

5.67 

5.8 

5.95 

6.11 

6.26 

6.41 

6.56 

6.72 

6.87 

22 

.47 

4.63 

4.79 

4.95 

5,11 

5.27 

5.43 

5.59 

5.75 

5.9 

6.06 

6.22 

6.38 

6.54 

6.7 

6.86 

7.02 

7.18 

23 

.06 

4.83 

5. 

5.16 

5.33 

5.5 

5.66 

5.83 

6. 

6.16 

6.33 

6.5 

6.66 

6.83 

7. 

7.16 

7.33 

7.5 

24 

.80 

5.03 

5.2 

5.38 

5.55 

5.72 

5.9 

6.07 

6.25 

6.42 

6:59 

6.77 

6.94 

7.11 

7.29 

7.46 

7.63 

7.81 

25 

.05 

5.23 

5.41 

5.45 

5.77 

5.95 

6.13 

6.31 

6.5 

6.68 

6.86 

7.04 

7.22 

7.4 

7.58 

7.76 

7.94 

8.12 

26 

.25 

5.43 

5.62 

5.81 

6. 

6.18 

6.37 

6.56 

6.75 

6.93 

7.12 

7.24 

7.5 

7.68 

7.87 

8.06 

8.25 

8.43 

27 

.44 

5.63 

5.83 

6.02 

6.22 

6.4 

6.61 

6.8 

7. 

7.19 

7.38 

7.58 

7.77 

7.97 

8.16 

8.36 

8.55 

8.75 

28 

.63 

5.84 

6.04 

6.24 

6.44 

6.64 

6.84 

7.04 

7.25 

7.45 

7.65 

7.8 

8.05 

8.25 

8.45 

8.65 

8.86 

9.06 

29 

.83 

6.04 

6.25 

6.45 

6.66 

6.87 

7.08 

7.29 

7.5 

7.7 

7.91 

8.12 

8.33 

8.54 

8.75 

8.95 

9.16 

9.37 

30 

.02 

6.24 

6.45 

6.67 

6.88 

7.1 

7.31 

7.53 

7.75 

7.96 

8.18 

8.39 

8.61 

8.82 

9.04 

9.25 

9.47 

9.68 

31 

.22 

6.44 

6.66 

6.88 

7.1 

7.33 

7.55 

7.77 

8. 

8.22 

8.44 

8.66 

8.88 

9.11 

9.33 

9.55 

9.77 

10. 

32 

.4 

6.64 

6.87 

7.1 

7.33 

7.56 

7.79 

8.02 

8.25 

8.47 

8.7 

8.93 

9.16 

9.39 

9,62 

9.85 

10.08 

10.31 

33 

.61 

6.84 

7.08 

7.31 

7.55 

7.79 

8.02 

8.26 

8.5 

8.73 

8.97 

9.2 

9.44 

9.68 

9.91 

10.15 

10.38 

10.62 

34 

.8 

7.04 

7.29 

7.53 

7.77 

8.02 

8.26 

8.5 

8.75 

9. 

9.23 

9.47 

9.72 

9.89 

10.2 

10.45 

10.69 

10.93 

35 

. 

7.25 

7.5 

7.75 

8. 

8.25 

8.5 

8.75 

9. 

9.25 

9.5 

9.75 

10. 

10.25 

10.5 

10.75 

11. 

1.25 

36 

.19 

7.45 

7.7 

7.96 

8.22 

8.47 

8.73 

9. 

9.25 

9.5 

9.76 

10.02 

10.27 

10.53 

10.79 

11.04 

11.3 

1.56 

37 

.38 

7.65 

7.91 

8.18 

8.44 

8.7 

8.97 

9.23 

9.5 

9.76 

10.02 

10.29 

10.55 

10.81 

11.08 

11.34 

1.61 

11.87 

38 

.58 

7.8 

8.12 

8.39 

8.66 

8.93 

9.2 

9.47 

9.75 

0.02 

10.29 

10.56 

10.83 

11.1 

11.37 

11.64 

1.91 

12.11 

39 

.77 

8.05 

8.33 

8.61 

8.88 

9.16 

9.44 

9.72 

10. 

0.27 

10.55 

10.83 

11.11 

1.38 

11.66 

11.94 

2.12 

2.5 

40 

.97 

8.25 

8.54 

8.82 

9.11 

9.39 

9.68 

9.89 

10.25 

0.53 

10.81 

11.1 

11.38 

11.67 

11.95 

2.24 

2.52 

2.81 

41 

.16 

8.45 

8.75 

9.04 

9.33 

96? 

9.91 

10.2 

0.5 

079 

1108 

11  37 

11  66 

195 

12  25 

254 

283 

3  12 

42 

.36 

8.65 

8.95 

9.25 

9.55 

9.85 

10.15 

10.45 

0.75 

1.04 

11.34 

11.64 

11.94 

12.24 

12.54 

2.84 

3.13 

3.43 

43 

.55 

8.86 

9.16 

9.47 

9.77 

10.08 

10.38 

10.69 

11. 

1.3 

11.61 

11.91 

12.12 

12.52 

2.83 

3.13 

3.44 

3.75 

44 

.75 

9.06 

9.37 

9.68 

10. 

10.31 

10.62 

10.93 

11.25 

1.56 

11.87 

12.11 

12.5 

2.81 

3.12 

3.43 

3.75 

4.06 

45 

NO   DEDUCTION    HAS    BEEN   MADE    HERE    FOR   REGISTERS   OR   GRILLS. 


192 


THE    SCHOOL   HOUSE. 


TABLE  16. 
AREAS  AND  CIRCUMFERENCE  OF  CIRCLES. 


Diaui. 
In. 

Area. 
Sq.  Ft. 

Circum- 
ference. 

Ft. 

Diam. 
In. 

Area. 
Sq.  Ft. 

Circum- 
ference. 

Ft. 

Diam. 
In. 

Area. 
Sq.  Ft. 

Circum- 
ference. 

Ft. 

1 

.0055 

.2618 

29 

4.587 

7.592 

57 

17.72 

14.92 

2 

.0218 

.5236 

30 

4.909 

7.854 

58 

18.35 

15.18 

3 

.0491 

.7854 

31 

5.241 

8.116 

59 

18.99 

15.45 

4 

.0873 

1.047 

32 

5.585 

8.378 

60 

19.63 

15.71 

5 

.1364 

1.309 

33 

5.940 

8.639 

61 

20.29 

15  97 

6 

.1964 

1.571 

34 

6.305 

8.901 

62 

20.97 

16.23 

7 

.2673 

1.833 

35 

6.681 

9.163 

63 

21.65 

16.49 

8 

.3491 

2.094 

36 

7.069 

9.425 

64 

22.34 

16.76 

9 

.4418 

2.356 

37 

7.467 

9.686 

65 

23.04 

17.02 

10 

.5454 

2.618 

38 

7.876 

9.948 

66 

23.76 

17.28 

11 

.6600 

2.880 

39 

8.276 

10.21 

67 

24.48 

17.54 

12 

.7854 

3.142 

40 

8.727 

10.47 

68 

25.22 

17.80 

13 

.9218 

3.403 

41 

9.168 

10.73 

69 

25.97 

18.06 

14 

1.069 

3.665 

42 

9.621 

ltf.99 

70 

26.73 

18.33 

15 

1.227 

3.927 

43 

10.08 

11.26 

71 

27.49 

18.59 

16 

1.396 

4.189 

44 

10.56 

11.52 

72 

28.27 

18.85 

17 

1.576 

4.451 

45 

11.04 

11.78 

73 

29.07 

19.11 

18 

1.767 

4.712 

46 

11.54 

12.04 

74 

29.87 

19.37 

19 

1.969 

4.974 

47 

12.05 

12.30 

75 

30.68 

19  63 

20 

2.182 

6.236 

48 

12.57 

12.57 

76 

31.50 

19.90 

21 

2.405 

5.498 

49 

13.10 

12.86 

77 

32.34 

20.16 

22 

2.640 

5.760 

50 

13.64 

13.09 

78 

33.18 

20.42 

23 

2.885 

6.021 

51 

14.19 

13.35 

79 

34.04 

20.68 

24 

3.142 

6.283 

52 

14.75 

13.61 

80 

34.91 

20.94 

25 

3.409 

6.545 

53 

15.32 

13.88 

81 

35.78 

21.21 

26 

3.687 

6.807 

54 

15.90 

14.14 

82 

36.67 

21.47 

27 

3.976 

7.069 

55 

16.50 

14.40 

83 

37.57 

21.73 

28 

4.276 

7.330 

56 

17.10 

14.66 

84 

38.48 

21.99 

THE    SCHOOL   HOUSE. 


193 


TABLE  17. 
FOR  EQUALIZING  THE  DIAMETER  OF  PIPES. 

The  number  at  the  intersection  of  lines  and 
columns,  headed  by  heavy  figures,  shows  the  number 
^  of  smaller  pipes  that  the  larger  one  is  equal  to  for 
8  IX.  convevinr  air.  etc.  For  example:  one  14-inch  pipe 

w/7/  convey  as  much  air  (friction  considered)  as  13 
Jive-inch  —  13  being  at  the  intersection  of  column 
»,.  marked  5  and  line  marked  14. 

/ 

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194 


THE    SCHOOL    HOUSE. 


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THE    SCHOOL    HOUSE. 

TABLE   19. 

CAPACITY  OF  PIPES  AND  REGISTERS. 
ROUND  PIPES. 


195 
/ 


Diameter 
of  Pipe 

Area  in 
Sq.  Inches. 

Diameter 
of  Pipe. 

Area  in 
Sq.  Inches. 

Diameter 
of  Pipe.    , 

Area  in 
Sq.  Inches. 

7  in. 

38 

12  in. 

113 

22  in. 

380 

8  in. 

50 

14  in. 

154 

24  in. 

452 

9  in. 

63 

16  in. 

201 

26  in. 

531 

10  in. 

78 

18  in. 

254 

28  in. 

616 

11  in. 

95 

20  in. 

314 

30  in. 

707 

REGISTERS. 


Size  of 
Opening. 

Capacity  in 
Sq.  Inches. 

Size  of 
Opening. 

Capacity  in 
Sq.  Inches. 

Size  of 
Opening. 

Capacity  in 
Sq.  Inches. 

6X10 

40 

10X14 

93 

20X20 

267 

8X10 

53 

10X16 

107 

20X24 

320 

8X12 

64 

12X15 

120 

20X26 

347 

8X15 

80 

12X19 

152 

21X29 

406 

9X12 

72 

14X22 

205 

27X27 

486 

9X14 

84 

15X25 

250 

27X38 

684 

10X12 

80 

16X24 

256 

30X30 

600 

ROUND   REGISTERS. 


Size  of 
Opening. 

Capacity  in 
Sq.  Inches. 

Size  of     '. 
Opening. 

Capacity  in 
Sq.  Inches. 

Size  of 
Opening. 

Capacity  in 
Sq.  Inches. 

7  in. 

26 

12  in. 

75 

20  in. 

209 

8  in. 

33 

14  in. 

103 

24  in. 

301 

9  in 

42 

16  in. 

134 

30  in. 

471 

10  in. 

52 

18  in. 

169 

36  in. 

679 

DIMENSIONS  OF  CAST-IRON   REGISTERS. 

(TUTTLE    AND    BAILEY.) 


Size. 
Inches. 

Net  Area. 
Square  Feet. 

Size. 
Inches. 

Net  Area. 
Square  Feet. 

10X12 

.55 

16X24 

1.77 

10X14 

.64 

16X26 

1.92 

10X16 

.74 

18X24 

2.00 

12X15 

.83 

18X30 

2.50    , 

12X16 

.88 

20X20 

1.85 

12X19 

1.05 

20X24 

2.22 

14X18 

1.16 

20X26 

2.41 

14X22 

1.42 

21X29 

2.82 

15X25 

1.73 

24X32 

3.55 

16X16 

1.18 

27X27 

3.37 

16X20 

1.48 

27X38 

4.75 

16X21 

1.55 

30X30 

4.16 

196 


THE    SCHOOL   HOUSE. 


TABLE  20. 

WEIGHTS  OF  £  AND  H  STEEL  PER  LINEAL  FOOT 
(Based  on  489.6  Ibs.  $er  cubic  foot.) 


Size. 
I  aches. 

Wt.  of  O 
1  ft.  long 

Wt.  of  • 
1  ft.  long. 

Size. 
Inches. 

Wt.  of  • 
1  ft.  long 

Wt.  of  • 
1  ft.  long 

Size. 
Inches 

Wt.  of  • 
1  ft.  long. 

Wt.ofH 
1  ft.  long. 

o_V 

.0026 

.0033 

3 

24.03 

30.60 

6 

96.14 

122.4 

O'iV 

.0104 

.0133 

3- 

V- 

25.04 

31.89 

&-lg 

98.14 

125.0 

Oi 

.0417 

.0531 

3£ 

26.08 

33.20 

gl 

100.2 

127.6 

OA 

.0938 

.1195 

ift 

27.13 

34.55 

6iao 

102.2 

130.2 

04- 

.1669 

.2123 

31 

28.20 

35.92 

61 

104.3 

132.8 

Oft 

.2608 

.3333 

3-i 

V 

29.30 

37.31 

106.4 

135.5 

Of 

.3756 

.4782 

S3 

30.42 

38.73 

|* 

108.5 

138.2 

oft 

.5111 

.6508 

3i 

31.56 

40.18 

110.7 

140.9 

o* 

.6676 

.8500 

3i 

32.71 

41.65 

6t 

112.8 

143.6 

Oft 

.8449 

1.076 

ift 

33.90 

43.14 

114.9 

146.5 

0| 

1.043 

1.328 

3| 

35.09 

44.68 

w 

117.2 

149.2 

OH 

1.262 

1.608 

3} 

i 

36.31 

46.24 

119.4 

152.1 

of 

1.502 

1.913 

3^ 

37.56 

47.82 

8f 

121.7 

154.9 

oil 

1.763 

2.245 

3-j 

3- 

38.81 

49.42 

6|I 

123.9 

157.8 

°L 

2.044 

2.603 

3j 

40.10 

51.05 

126.2 

160.8 

2.347 

2.989 

3tf 

41.40 

52.71 

all 

128.5 

163.6 

1 

2.670 

3.400 

4 

42.73 

54.40 

7 

130.9 

166.6 

ir 

3.014 
3.379 

3.838 
4.303 

Jj 

V 

• 

44.07 
45.44 

56.11 

57.85 

1 

135.6 
140.4 

172.6 

178.7 

ift 

3.766 

4.795 

4l 

36 

46.83 

59.62 

145.3 

184.9 

il 

4.173 

5.312 

4' 

48.24 

61.41 

72 

150.2 

191.3 

i-j^. 

4.600 

5.857 

k 

49.66 

63.23 

7| 

155.2 

197.7 

if 

5.019 

6.428 

*i 

•  . 

51.11 

65.08 

74 

160.3 

204.2 

ift 

5.518 

7.026 

h 

52.58 

66.95 

78 

165.6 

210.8 

H 

6.008 

7.650 

4 

54.07 

68.85 

8 

171.0 

217.6 

i-*«r 

6.520 
7.051 

8.301 
8.978 

if 

55  59 
57.12 

70.78 
72.73 

8| 

176.3 
181.8 

224.5 
231.4 

itt 

7.604 

9.682 

i 

58.67 

74.70 

8f 

187.3 

238.5 

i 

8.178 

10.41 

4 

60.25 

76.71 

8i 

193.0 

245.6 

i1! 

8.773 

11.17 

4, 

1- 

w 

61.84 

78.74 

8f 

198.7 

252.9 

i2- 

9.388 

11.95 

£ 

' 

63.46 

80.81 

84 

204.4 

260.3 

l^i 

10.02 

12.76 

*\ 

9  ' 

65.10 

82.89 

88 

210.3 

267.9 

2 

10.68 

13.60 

5 

66.76 

85.00 

9 

216.3 

275.4 

2iV 

11.36 

14.46 

5-i 

». 

68.44 

87.14 

91 

222.4 

283  2 

12.06 

15.35 

4" 

70.14 

89.30 

91 

228.5 

290.9 

2ft 

12.78 

16.27 

5] 

V 

71.86 

91.49 

9f 

234.7 

298.9 

21 

13.52 

17.22 

51 

73.60 

93.72 

9| 

241.0 

306.8 

2A 

14.28 

18.19 

Si 

fe 

75.37 

95.96 

95. 

247.4 

315.0 

2t 

15.07 

19.18 

& 

i 

77.15 

98.23 

9| 

253.9 

323.2 

2iV 

15.86 

20.20 

k 

78.95 

100.5 

9| 

260.4 

331.6 

2l 

16.69 

21.25 

4 

80.77 

102.8 

10 

267.0 

340.0 

17.53 

22.33 

5i 

v 

82.62 

105.2 

101 

280.6 

357.2 

2h 

18.40 
19.29 

23.43 
24.56 

5 
5 

° 

[i 

84.49 
86.38 

107.6 
110.0 

si 

294.4 

308.6 

374.9 
392.9 

2f 

20.20 

25.00 

5 

88.29 

112.4 

11 

323.1 

411.4 

2it 

21.12 

26.90 

5 

1 

90.22 

114  9 

111 

337.9 

430.3 

28 

22.07 

28.10 

5- 

92.17 

117.4 

H~2 

353.1 

4496 

21* 

23.04 

29.34 

V 

1 

94.14 

119.9 

llf 

368.6 

469.4 

These  figures  represent  the  theoretical  weights  of  steel.     Iron  will   run 
about  2  per  cent  lighter. 


THE   SCHOOL   HOUSE. 


197 


TABLE  21. 
STANDARD  GAUGES. 


U.S.  STANDARD  GAUGE. 

BIRMINGHAM  GAUGE. 

No.  of 
Gauge. 

Thickness  in  Inches. 

Weight  Square  Foot. 

No.  of 
Gauge. 

Thick- 
ness in 
Inches. 

Weight  Sq.  Foot. 

fractions. 

Decimals. 

Iron. 

Steel. 

Iron. 

Steel. 

7-0's 

i. 

.5 

20.00 

20.4 





_ 

_ 

6-0's 

3~f 

.46875 

18.75 

19.125 









5-0's 

jC 

.4375 

17.50 

17.85 









0000 

32 

.40625 

16.25 

16.575 

0000 

.454 

18.22 

18.46 

000 

^ 

.375 

15. 

15.30 

000 

.425 

17.05 

17.28 

00 

3~2 

.34375 

13.75 

14.025 

00 

.38 

15.25 

15.45 

0 

V 

.3125 

12.50 

12.75 

0 

.34 

13.64 

13.82 

1 

ft 

.28125 

11.25 

11.475 

1 

.3 

12.04 

12.20 

2 

V 

.265625 

10.625 

10.8375 

2 

.284 

11.40 

11.55 

.    3 

i. 

.25 

10. 

10.2 

3 

.259 

10.39 

10.53 

4 

6"4 

.234375 

9.375 

9.5625 

4 

.238 

9.55 

9.68 

5 

-h 

.21875 

8.75 

8.925 

5 

.22 

8.83 

8  95 

6 

8 

.203125 

8.125 

8.2875 

6 

.203 

8.15 

8.25 

7 

-h 

.1875 

7.5 

7.65 

7 

.18 

7.22 

7.32 

8 

it 

.171875 

6.875 

7.0125 

8 

.165 

6.62 

6.71 

9 

ft 

.15625 

6.25 

6.375 

9 

.148 

5.94 

6.02 

10 

A 

.140625 

5.625 

5.7375 

10 

.134 

5.38 

5.45 

11 
12 

* 

.125 
.109375 

5. 
4.375 

5.1 
4.625 

11 

12 

.12 
.109 

4.82 
4.37 

4.88 
4.43 

13 

.09375 

3.75 

3.825 

13 

.095 

3.81 

3.86 

14 

eV 

.078125 

3.125 

3.1875 

14 

.083 

3.33 

3.37 

15 

T*7 

.0703125 

2.8125 

2.86875 

15 

.072 

2.89 

2.93 

16 

A 

.0625 

2.5 

2.55 

16 

.065 

2.61 

2.64 

17 

160 

.05625 

2.25 

2.295 

17 

.058 

2.33 

2.36 

18 

.05 

2. 

2.04 

18 

.049 

1.97 

1.99 

19 

T&o" 

.04375 

1.75 

.785 

19 

.042 

1.69 

1.71 

20 

.0375 

1.50 

.53 

20 

.035 

1.40 

1.42 

21 

sVo 

.034375 

1.375 

.4025 

21 

.032 

1.28 

1.30 

22 

.03125 

1.25 

.275 

22 

.028 

1.12 

1.14 

23 

_  a.— 

.028125 

1.125 

.1475 

23 

.025 

1.00 

1.02 

24 

"40" 

.025 

1. 

.02 

24 

.022 

.883 

.895 

25 

F2"0 

.021875 

.865 

.8925 

25 

.02 

.803 

.813 

26 

T60" 

.01875 

.75 

.765 

26 

.018 

.722 

.732 

27 

aYo 

.0171875 

.6875 

.70125 

27 

.016 

.642 

.651 

28 

(fr 

.015625 

.625 

.6375 

28 

.014 

.562 

.569 

29 

6"4"0 

.0140625 

.5625 

.57375 

29 

.013 

— 

— 

30 

A 

.0125 

.5 

.51 

30 

.012 

— 

— 

31 

_JL_ 

.010985 

.4375 

.44625 

31 

.01 

— 

— 

32 

Tllo" 

.01045625 

.40625 

.414375 

32 

.009 

— 

— 

33 

3"  20" 

.009375 

.375 

.3825 

33 

.008 

— 

— 

34 

_LJ  

.00859375 

.34375 

.350625 

34 

.007 





35 

a!o 

.0078125 

.3125 

.31875 

35 

.005 

— 

— 

36 

1  28TT 

.00703125 

.28125 

.286875 

36 

.004 

— 

— 

37 

.00664062 

.265625 

.2709375 

37 

— 



— 

38 

Tio° 

.00625 

.25 

.255 

— 

— 

— 

— 

All  sheets  of  iron  and  steel  are  rolled  to  U.S.  standard  gauge  unless 
otherwise  ordered. 

The  low  temperature  (as  compared  with  iron)  at  which  steel  plates  have 
to  be  finished,  causes  a  slight  springing  of  the  rolls,  leaving  the  plate  thicker 
in  the  center  than  on  the  edge.  This  is  especially  noticeable  in  plates  less 
than  y%  inch  thick  and  over  66  inches  wide,  which  may  be  of  full  thickness 
on  the  edge  and  yet  be  as  much  as  l/%  inch  thicker  in  the  middle. 


198 


THE    SCHOOL    HOUSE. 


TABLE   22 
ESTIMATED  WEIGHTS  OF  GALVANIZED  SHEETS. 


U.S.  Stan- 
dard Gauge 

10 

12 

14 

16 

18 

20 

22 

24 

25 

26 

27 

28 

29 

30 

Weight  per  ) 
sq.ft.,  Ibs  | 

5.781 

4.531 

3.281 

2.656 

2.156 

1.656 

1406 

1.156 

1.031 

.9062 

.8437 

.7812 

.7187 

.6562 

Weight  per  I 

92.5 

72.5 

52.5 

42.5 

34.5 

26.5 

22.5 

18.5 

16.5 

14.5 

13.5 

12.5 

11.5 

10.5 

sq.  ft.,  oz.  ( 

Size  of 
Sheet 

WEIGHT  OF  SHEET  —  POUNDS 

24  x  72 

69 

54 

39 

32 

26 

20 

17 

14 

12 

11 

10 

9 

9 

8 

24  x  84 

81 

63 

46 

37 

30 

23 

20 

16 

14 

13 

12 

11 

10 

9 

24  x  96 

93 

73 

53 

43 

35 

27 

23 

19 

17 

15 

14 

13 

12 

11 

24  x  120 

116 

91 

66 

53 

43 

33 

28 

23 

21 

18 

17 

16 

14 

13 

26  x  72 

75 

59 

43 

35 

28 

22 

18 

15 

13 

12 

11 

10 

9 

9 

26  x  84 

88 

69 

50 

40 

33 

25 

21 

18 

16 

14 

13 

12 

11 

10 

26  x  96 

100 

79 

57 

46 

37 

29 

24 

20 

18 

16 

15 

14 

12 

11 

26  x  120 

125 

98 

71 

58 

47 

36 

30 

25 

22 

20 

18 

17 

16 

14 

28  x  72 

81 

63 

46 

37 

30 

23 

20 

16 

14 

13 

12 

11 

10 

9 

28  x  84 

94 

74 

54 

43 

35 

27 

23 

19 

17 

15 

14 

13 

12 

11 

28  x  96 

108 

85 

61 

50 

40 

31 

26 

22 

19 

17 

16 

15 

13 

12 

28  x  120 

135 

106 

77 

62 

50 

39 

33 

27 

24 

21 

20 

18 

17 

15 

30  x  72 

87 

68 

49 

40 

32 

25 

21 

17 

15 

14 

13 

12 

11 

10 

30  x  84 

101 

79 

57 

46 

38 

29 

25 

20 

18 

16 

15 

14 

13 

11 

30  x  96 

116 

91 

66 

53 

43 

33 

28 

23 

21 

18 

17 

16 

14 

13 

30  x  120 

145 

113 

82 

66 

54 

41 

35 

29 

26 

23 

21 

20 

18 

16 

36  x  72 

104 

82 

59 

48 

39 

30 

25 

21 

19 

16 

15 

14 

13 

12 

36  x  84 

121 

95 

69 

55 

45 

35 

30 

24 

22 

19 

18 

16 

15 

14 

36  x  96 

139 

109 

79 

64 

52 

40 

34 

28 

25 

22 

20 

19 

17 

16 

36  x  120 

173 

136 

98 

80 

65 

50* 

42 

35 

31 

27 

25 

23 

22 

20 

42  x  72 

121 

95 

71 

56 

45 

34 

29 

24 

22 

19 

18 

16 

15 

14 

42  x  84 

142 

111 

80 

65 

53 

41 

34 

28 

25 

22 

21 

19 

18 

16 

42  x  96 

162 

127 

92 

74 

60 

46 

39 

32 

29 

25 

24 

22 

20 

18 

42  x  120 

202 

159 

115 

93 

75 

58 

49 

41 

36 

33 

29 

27  ' 

25 

23 

48  x  72 

139 

109 

79 

64 

52 

40 

34 

28 

25 

22 

20 

19 

17 

16 

48  x  84 

16-2 

125 

92 

74 

60 

46 

39 

32 

29 

25 

24 

22 

20 

18 

48  x  96 

185 

145 

105 

85 

69 

55 

45 

37 

33 

29 

27 

25 

23 

21 

48  x  120 

231 

181 

131 

106 

86 

66 

56 

46 

41 

36 

34 

31 

29 

THE    SCHOOL   HOUSE. 


199 


TABLE    23. 

CIRCUMFERENCES  OF  CIRCLES. 
COMPREHENDING  DIAMETERS  USED  BY  BOILER  MAKERS. 


Diameter  in 
Inches. 

Circumference 
in  Inches. 

Area  in 
Sq.  Inches. 

Diameter  in 
Inches. 

Circumference 
in  Inches 

Area  in 
Sq.  Inches 

12 

37| 

113 

58 

182* 

2642 

14 

44 

154 

60 

188| 

28271 

16 

50| 

201 

62 

194* 

3019 

18 

564 

2541 

64 

201 

3217 

20 

62f 

314& 

66 

207* 

,34211 

22 

380i 

68 

2181 

363l| 

24 

75| 

452  1 

70 

219& 

38481/ 

26 

531 

72 

226| 

4071^ 

28 

871 

615| 

74 

232f 

4300J 

30 

94| 

706  1 

76 

238| 

4536^ 

32 

100} 

804| 

78 

244& 

4478| 

34 

1061 

908 

80 

2514 

50261 

36 

113 

10171 

82 

257^ 

5281 

38 

1191 

H344 

84 

263| 

6541f 

40 

125| 

1256| 

86 

270£ 

5808J 

42 

131| 

13851 

88 

276^- 

6082^ 

44 

188} 

1520} 

90 

28  2  1 

8861} 

46 

144i 

1662 

92 

289 

6647| 

48 

150| 

18091 

94 

295| 

6939f 

50 

157 

19631 

96 

3011 

7238| 

52 

1631 

2128| 

98 

307i 

7543 

54 

169| 

2290| 

100 

3141 

7854 

56 

175| 

2463 

102 

320f 

81711 

Boilermakers  usually  add  three  times  the  thickness  of  the  plate  to  length 
of  iron  for  the  take-up  in  rolling;  also  add  for  laps,  single  or  double  riveting. 


TABLE   24. 
NUMBER  OF   TUBES   USUALLY   PUT   IN   RETURN  TUBULAR  BOILERS. 


HAND-HOLES  UNDER  TUBES. 


MANHOLE  UNDER  TUBES. 


Diam.       2i-Inch 
Boiler.       Tubes. 

3-Inch 
Tubes. 

SHnch 
Tubes. 

4-Inch 
Tubes. 

Diam. 

3-Inch 
Tubes. 

3i-Inch 
Tubes. 

4-Inch 
Tubes. 

36             38 

26 

_ 

_ 

_ 

_ 

_ 

_ 

42 

52 

38 

_ 

_ 

42 

_ 

22 

18 

44 

_ 

38 

34 

22 

44 

28 

26 

20 

48 

_ 

52 

38 

34 

48 

44 

28 

26 

54 

_ 

54 

44 

34 

54 

56 

44 

36 

60 

_ 

82 

64 

54 

60 

62 

54 

44 

66 

_ 

_ 

72 

54 

66 

88 

66 

54 

72 

_ 

_ 

92 

72 

72 

124 

86 

70 

- 

- 

- 

- 

- 

78 

132 

100 

84 

200 


THE   SCHOOL   HOUSE. 


TABLE   25. 
DIMENSIONS  OF  STANDARD  WROUGHT  IRON  PIPE. 


INCHES. 

ACTUAL 
DIAMETER. 

THICKNESS. 
INCHES. 

CIRCUMFERENCE. 
INCHES. 

LENGTH  OF  PIPE 

IN   FEET   PER 

SQUARE  FOOT 
OF  SURFACE. 

AREA. 
SQUARE  INCHES. 

Nominal 
Inside 
Diam. 

Inside. 

Outside. 

Internal. 

External. 

Inside. 

Outside. 

Internal. 

External. 

i 

.27 

.40 

.07 

.84 

1.27 

14.15 

9.44 

.06 

.12 

1 

4 

.36 

.54 

.08 

1.14 

1.69 

10.50 

7.07 

.10 

.22 

1 

.49 

.67 

.09 

1.55 

2.12 

7.67 

5.65 

.19 

.35 

.62 

.84 

.10 

1.95 

2.65 

6.13 

4.50 

.30 

.55 

| 

.82 

1.05 

.11 

2.58 

3.29 

4.63 

3.63 

.53 

.86 

1 

1.04 

1.31 

.13 

3.29 

4.13 

3.67 

2.90 

.86 

1.35 

H 

1.38 

1.66 

.14 

4.33 

5.21 

2.76 

2.30 

1.49 

2.16 

ij 

1.61 

1.90 

.14 

5.06 

5.96 

2.37 

2.01 

2.03 

3.83 

2 

2.06 

2.37 

.15 

6.49 

7.46 

1.84 

1.61 

3.35 

4.43 

2£ 

2.46 

2.87 

.20 

7.75 

9.03 

1.54 

1.32 

4.78 

6.49 

3 

3.06 

3.50 

.21 

9.63 

10.96 

1.24 

1.09 

7.38 

9.62 

|H 

3.56 

4.00 

.22 

11.14 

12.56 

1.07 

.95 

9.83 

12.50 

4 

4.02 

4.50 

.23 

12.64 

14.13 

.94 

.84 

12.73 

15.90 

H 

4.50 

5.00 

.24 

14.15 

15.70 

.84 

.76 

15.93 

19.63 

5 

5.04 

5.56 

.25 

15.84 

17.47 

.75 

.62 

19.99 

24.30 

6 

6.06 

6.62 

.28 

19.05 

20.81 

.63 

.57 

28.88 

34.47 

7 

7.02 

7.62 

.30 

22.06 

23.95 

.54 

.50 

38.53 

45.66 

8 

7.98 

8.62 

.32 

25.07 

27.09 

.47 

.44 

50.03 

58.42 

9 

9.00 

9.68 

.34 

28.27 

30.43 

.42 

.40 

63.63 

73.71 

10 

10.01 

10.75 

.36 

31.47 

33.77 

.38 

.35 

78.83 

90.79 

11 

11.00 

11.75 

.37 

34.55 

36.91 

.34 

.32 

95.03 

108.43 

12 

12.00 

12.75 

.37 

37.70 

40.05 

.32 

.30 

113.09 

127.67 

13 

13.25 

14.00 

.37 

41.62 

43.98 

.29 

.27 

137.88 

153.94 

14 

14.25 

15.00 

.37 

44.76 

47.12 

.27 

.25 

159.48 

167.71 

15 

15.40 

16.00 

.28 

48.48 

50.26 

.25 

.24 

187.04 

201.06 

TABLE  26. 
EXPANSION  OF  METALS. 

The  Linear  Expansion,  or  Extension  of  Metals  for  One  Degree  Rise 
in   Temperature. 


Material. 

Increase  of  Length  in 
One  Foot  for  an  Increase 
in  Temperature  of  1°  F. 

Material. 

Increase  of  Length  in 
One  Foot  for  an  Increase 
in  Temperature  of  1°  F. 

Cast-Iron 
Wrought-Iron 
Steel  Tubes 
Copper 

.0000740 

.0000823 
.0000719 
.0001146 

Brass 
Zinc 
Lead 
Tin 

.0001244 

.0001961 
.0001900 
.0001692 

To  find  the  amount  of  expansion  or  contraction  of  a  bar  or  pipe  of 
given  length,  which  will  be  caused  by  a  given  change  in  tempera- 
ture, multiply  the  length  in  feet  by  the  number  of  degrees  of  change 
in  temperature.  Multiply  this  product  by  the  co-efficient  given  in 


THE    SCHOOL    HOUSE. 


201 


the  table  for  the  material  employed.  The  result  will  be  the  change 
in  length  in  inches. 

Iron  pipes  which  are  used  in  steam  and  hot-water  fitting  expand 
about  one  and  one-half  inches  for  100  feet  in  length. 

In  long  lines  of  pipe  this  expansion  must  be  provided  for ;  other- 
wise it  will  make  trouble  by  breaking  connections  or  shoving  appa- 
ratus out  of  place. 

TABLE  27. 
FOR  ESTIMATING  SIZE  OF  COAL-BIN. 


CUBIC  FEET  IN  ONE  TON. 

Kind  of  Coal. 

Short  Ton,  2,000  Ibs. 

Long  Ton,  2,240  Ibs. 

Broken 
Egg 
Stove 
Nut 
Pocahontas 

33. 
33.6 
34.2 
35. 
36. 

37. 
37.6 
38  2 
39.2 
40.2 

The  following  is  from  tests  by  Mr.  D.  P.  Sullivan,  Sealer  of  Weights 
and  Measures,  Boston,  Mass. 


Kind  of  Coal. 

One  Ton. 

Cubic  Feet.    Cubic  Inches 

White  Ash 

Stove 

37               116 

White  Ash  (egg) 

Stove 

36                 36 

Shamokin 

Stove 

37               662 

Lackawanna  (nut) 

Stove 

31               857 

Franklin  (Lykens  Valley) 
Lehigh  (hard  egg) 

Stove                      , 
Furnace 

38               164 
33               576 

Lehigh  (free  burning) 

Furnace 

36                 62 

Lackawanna  (free  burning) 

Furnace 

38               796 

New  River 

Soft  Steam 

36             1295 

Cumberland 

Blacksmiths' 

30               723 

INDEX 


Air,  amount  heated 75,  98 

amount  for  respiration  .  .  24,  27 
amount  for  ventilation  .  .  28,41 

carbonic  acid  in 24-29 

carbonic  oxide  in 25 

circulation   of 

.    .    .  .35,  44-52,  54,  57,  58,  59,  65 

composition  of 24,  25 

humidity  of. 28,  29 

impurities  in 24-27 

leakage  in  school-rooms     . 

51,  54,  55,  61 

lime  water  test  for  carbonic 

acid  in 29-32 

measurement  of  ....  33,  35-39 
nitrogenous  poison  in.  .  .  25,  26 
supply  for  school-rooms.  . 

v.      50,  60,  61,  62 

temperature  of 

...  38,  39,  48,  49,  60,  61,  62,  75 
valves  in  radiators  ....  96 
velocity  at  inlets  .  .  36,  37,  51,  52 

vitiated  by  lights 29,  53 

volume  and  weight  ....    39,  48 

Anemometers 33-37 

Appropriation  for  building    .    .  6 

Architects  competition  plans  by  .     2,6 
Architects   to.  file    plans    with 

inspector 3 

Automatic  heat  control   .    .  98,  99,  100 

Basements 11,  12 

Bicycle  runs 12 

Blackboards 22 

Boiler,  care  and  management  of 

115-117 

cast  iron 76,  86,  87 

coal  burned  by  ....     74,  75,  78 

construction  of 75-80 

covering 185 

fittings  required  for  ...  87,  92 
and  furnace  rooms  .  .  .  .  11,  12 

grates  for 75,  76,  78 

heating  surface  of  .  .  .  76,  77,  78 
horse-power  of  .  74,  81,  82,  83,  H9 
horizontal  tubular  .  76,  77,  81,  82 

inspection  of 90-92 

Massachusetts  laws  relating 

to 91,  92 

Massachusetts      inspectors' 

rule  for  pressure   ....          85 
U.S.  standard  for  pressure  85 

plans  of  settings  for    .         186-189 

safety  valves  for 

80,  87,  91,  92 

settings  for    ».    .    .    83-85,  186-189 


A  n\jw 

Boiler,  size  of 81,  82 

smoke  flues  for 76-79 

tubes  for 76,  79 

upright  tubular 76,  86 

water  tube 86 

Building    Committee,    appoint- 
ment of 2,  6 

Building,  construction  of  ...  8,9 
Care  of  heating  apparatus  .  .  108-119 
Casings  for  furnaces  ....  103,  137 

for  radiators 96,  97 

Cast  iron  furnaces 102 

Cast  iron  sectional  boilers     .    .    86,  87 

Cast  iron  registers 64,  195 

Chemical  laboratories     ....  12 

Chimneys  .  .  .  .  57,  58,  66-69,  71-73 
Circulation  of  air  35, 44, 46-54,  57-59,65 

Clocks      22 

Clothing-rooms 12,  13 

Coal,  amount  burned  .  .  .  74,  75,  78 
Cold-air  rooms  .  .  .12,105,109,110 
Combination  of  furnace  and  fan 

.    .    .     105,  106.  14.4,  146,  147,  148 
Combination    of    furnace     and 

steam  heat      

105,  144,  146,  147,  148,  152,  153 

Corridors 12,  13 

Cost  of  fuel 62 

of  ventilation  .  .  .42,  44,  62,  75 
Dampers  .  53,  54,^64,  65,  68,  111,  118 
Deflectors  and  diffusers  ....  53 

Desks 19,  20,  21 

Ducts  and  flues,  foul  air     .    .    . 

52,  54-58,  61,  62,  66-70 

Ducts  and  flues,  warm  air  51,  52,  63-65 
Engineers  and  firemen,  licensed  88-90 
Erroneous  ideas  of  ventilation  .  42-44 

Exits 14,  15 

Fans 50,  56,  69.  105,  106 

Fire,     means     for      preventing 

spread  of 3,  9,  10,  11 

Fire  escapes  on  school  houses  .  15 
Figures,  1-9,  school  house  .  . 

furniture 19,  20,  21 

10,  Professor  Wolpert's  Air 
Tester 30 

11,  Lime  Water  Apparatus         32 

12,  Template  for  correcting 
anemometer 34 

13  and  '4,  Form  of  air  inlet         35 
15.  16,  17  and  18,  measuring 

air  with  anemometer   .    .    36,  37 
19,  20,  21.  location  of  inlets 
and  outlets  and  circulation 
of  air  in  school-rooms    .    47,  48 


INDEX. 


203 


Firemen  and  Engineers,  licensed  88-90 

Flap  valves 54,  55,  58 

Foot  warmers 13,184,185 

Furnaces,  cast-iron 102 

and    fan,    combination     of 

105,  106 

grates  for 101 

and  hot  water,  combination 

of 105,  106 

location  of  ...  101,  103,  104,  111 

management  of 117-119 

pipes  for 105 

pit  for 103 

regulating    temperature    of 

103,  104 

setting  of 103 

size  of  ....        101 

smoke  pipes 103,  104 

and  steam-heat  combination 

of      105 

test  for  gas  leakage  ....        102 

twin  connected 105 

wrought  iron 102 

use  of,  in  school  buildings        101 
Galvanized  iron,  dampers  ...          54 
iron,    size    and    weight    of 

sheets 198 

iron  vent-flues 58 

Gas  engines 106 

lights 53 

Glass 13,  16 

Grates,  boiler 75,  76,  78 

furnace 101 

Heat,  automatic  control  of     .    .  98-100 

in  vent  flues 

....      66-70,  106,  107,  111,  112 
Heating  apparatus,  location  of  .    53,  54 

cost  of 62 

Height  of  school  buildings    .    .        7,  8 

Inlets,  air,  form  of 35 

air,  location  of  .    44,  46-49,  58,  64 
air,  size  of  ...   51,  60,  61,  63,  64 
Janitors,  duties  of  and  instruc- 
tions for 108-119 

Leakage  of  air 51,  55,  56 

Lime  water  test  for  purity  of  air  29-31 
apparatus  for  preparing  .    .     31-33 
Location  of  air-inlets  and  outlets 

.      35,  44, 

46-49,  58,  60,  61,  63,  64,  65,  68,  70 
of  heating  apparatus    53,  104,  105 
of  school  buildings       .    .       1,  6,  7 
Massachusetts  laws  for  construc- 
tion of  buildings  .    .    .  2,  3,  4,  5 
laws  for  inspection  of  steam- 
boilers      90,  91,  92 

laws  for  licensing  engineers 

and  firemen     ....     88,  89,  90 
requirements    to    prevent 

spread  of  fire  ....       9,  10,  11 
requirements  for  ventilation 
5,  41,  42 


PAGES 

Measurement  of  air     ...      33,  35-38 
Mixing  dampers  and  valves  .    . 

53,  64,  104,  iQT  HO 

Plans   for   and   descriptions    of 

schoolhouses,  Part  II.  127 

PLATES. 

I,  one-room  schoolhouse     128-130 

II  and  III,  one-room  portabler 
schoolhouse 130-133 

IV,    V    and   VI,    two-room, 

one-story  schoolhouse,     133-139 

VII,  VIII  and  IX.  two-room 

two-story  schoolhouse,    139-144 

X,  XI,  XII,  XIII  and  XIV, 
four-room,  two-story 
schoolhouse 144-148 

XV,  XVI  and  XVII,  five- 
room,  two -story  school- 
house  148-154 

XVIII,  XIX  and  XX,  six- 
room,  two-story  school- 
house  153-156 

XXI,  XXII,  XXIII,  XXIV, 
seven-room,  two-story 
schoolhouse 156-162 

XXV,  XXVI,  XXVII  and 
XXVIII,  eight-room,  two- 
story  schoolhouse  .  .  .  162-166 

XXIX,  XXX,  XXXI,  and 
XXXII,  eight-room,  two- 
story  schoolhouse  .  .  .  166-171 

XXXIII,  XXXIVandXXXV 
small  high  or  a  grammar 
schoolhouse  171-179 

XXXVI  and  XXXVII  sani- 
tary buildings  ....  180,  181 

XXXVIII,  direct-indirect 
radiator 179-182 

XXXIX,  portable    furnace 
for  small   hall  or  church 

183,  184 

XL,  foot-warmer  for  school- 
house  corridor   ....    184,  185 
XLI,  XLII  and  XLIII,  set- 
ting   for    one   horizontal 
tubular  boiler     ....     186-188 
XLIV,    section    of    setting 
for  two  horizontal  tubular 

boilers      189 

Plans,  competition 2,  6 

to  be  filed  with  inspector,  .  3 

Plenum  and  exhaust  systems    .... 

50,  51,  55 

Prevention  of  spread  of  fire  .    . 

. 3,  9,  10,  11 

Radiation,  direct 97,  98 

direct-indirect 97 

indirect 95-97,  99,  100 

Radiators,  casing 9n-!»7 

cast-iron 70,  95,  96 

piping 70,  93 

Rooms 17,  18,  23 


204 


INDEX. 


Sanitary  buildings  and  fixtures, 

care  of 120-126 

Seats 18,  19,  20,  21 

Stairs 12,  14,  15 

Stack-heaters     .      68,  69,  106,  107,  119 

Steam-pipes 69,  70,  93-95 

Steam-valves      94,  96 

Systems,  defective    ,..,..    42-46 
exhaust  and  plenum     .     50,  51,  55 
TABLES 

1,  for  Wolpert's  air  test     .    .      31 

2,  of   wind    velocity    and 
pressure 40 

3,  of  tests   of  amount   of 
heat   and   air  in  school- 
houses    60 

4,  of  tests   of   amount   of 
heat  and  air  in   school- 
houses    60 

5,  of  tests   of   amount   of 
heat  and  air  in   school- 
houses    61 

6,  of  tests   of   amount   of 
heat  and  air  in   school- 
houses    61 

7,  relative  cost  of  fuel  in 
schoolhouses 62 

8,  -of     boiler,    grate     and 
heating  surfaces 76 

9,  of  area  of  grate  surface 

and  tube  opening    ....       76 

10,  of  standard  boiler  tubes  .      77 

11,  standard  sizes  of  boilers 
....    81,  82 

12,  of  dimensions  of  brick 
settings  boilers 84 

13,  of  dimensions  of  brick 
settings  boilers 85 

14 ,  of  sizes   of  supply  and 
return  steam-pipes    ....      93 

15,  of  areas  of  rectangular 
openings 190,  191 

16,  of  areas  and  circumfer- 
ence of  circles    .  .    .    192 


TABLES. 

17,  for  equalizing  diameter 

of  pipes 193 

18,  of  number  of  gallons  in 
round  tanks  and  cisterns  .    194 

19,  of  capacity  of  pipes  and 
registers 195 

20,  of  weight  of  steel  bars 

per  foot 196 

21,  of  standard  gauges    .    .    .     197 

22,  of  weights  of  galvanized 
sheets 198 

23,  of    circumferences     of 
circles     used     by     boiler 
makers    .        199 

^  24,  of  number  of  tubes  used 

in  return  tubular  boilers  .    199 

25,  of  dimensions  of  stand- 
ard wrought-iron  pipe     .    .     200 

26,  of  expansion  of  metals  .    .    200 

27,  for   estimating    size   of 

coal  bins 201 

Temperature     in     school-rooms 

41,  60,  61,  62,  118 

Thermometers 22 

Try-cocks  in  water-pipes    ...  11 
Ventilation,    Massachusetts    re- 
quirements for 41,  42 

erroneous  ideas  of    .    .     4.2,  43,  44 
systems  of  ........    45,  46 

Vent-ducts,  flues  and  shafts  .    . 

....  54,  56,  57,  66-70,  106,  107 

Vestibules 14 

Warm-air  ducts  and  flues   .    .    .    63-65 

Water-motors 106 

Wind,  action  on  chimneys  and 

vent-flues  £~&~'$J.  .  .  63-65 
varying  conditions  or  .  .  .  56,70 
velocity  and  pressure  .  39,  40,  56 

Windows 13,  16,  17 

Wire  grills      64,  65 

Wolpert's  air  test 29,30,31 

Wooden    flues    and    ducts,    not 

allowed 3 


UNIVERSITY   OF    CALIFORNIA 
LIBRARY 

This  is  the  date  on  which  this 
book  was  charged  out. 

DUE  2  WEEKS  AFTER  DATE. 


NOV   2b 


[30m-6,'H] 


YC  57638 


